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U.S. Antarctic Program 1999-2000 National Science Foundation

U.S. Antarctic Program 1999-2000 i CONTENTS U.S. Antarctic Program, 1999-2000 ...... ii Aeronomy and Astrophysics ...... 1 Biology and Medicine ...... 12 Antarctic Pack Ice Seals ...... 25 Long-term ecological research ...... 28 Environmental Monitoring Program ...... 31 Geology and Geophysics ...... 32 Cape Roberts International Drilling Project ...... 47 Glaciology ...... 51 Siple Dome Ice Coring ...... 55 International Trans-Antarctic Scientific Expedition ...... 57 Ocean and Climate Systems ...... 60 ii

During the 1999-2000 austral summer and the Station by a team of scientists from the 1999-2000 ANTARCTIC U.S. PROGRAM, 2000 austral winter, the U.S. Antarctic Program United States, New Zealand, Italy, Australia, will support more than 800 researchers and the United Kingdom, and Germany other participants in the U.S. Antarctic Program • long-term ecological research in the at three year-round stations (McMurdo, McMurdo Dry Valleys and in the Palmer Amundsen-Scott South Pole, and Palmer), Station region of the Antarctic Peninsula aboard two research ships (Laurence M. Gould and Nathaniel B. Palmer) in the Ross Sea and in Science teams also will use networks of the Antarctic Peninsula region, at remote field automatic weather stations, automated geo- camps, and in cooperation with the national physical observatories, ultraviolet-radiation antarctic programs of the other Antarctic Treaty monitors, and a high-altitude, long-duration nations. These projects, funded and managed balloon that will circumnavigate the continent by the National Science Foundation (NSF), are and carry instruments for an optical investiga- part of the international effort to understand tion of solar activity. the Antarctic and its role in global processes. Eight teachers from U.S. elementary, mid- NSF also supports research that can be best or dle, and high schools will join researchers on only performed in Antarctica. eight projects this austral summer as part of The scientists who will conduct the proj- NSF’s Teachers Experiencing Antarctica (TEA) ects described in this book come primarily project. TEA immerses teachers in research as from U. S. universities and have won NSF part of their professional development and to support in response to Antarctic Research create a polar learning community of teachers, Program Announcement and Proposal Guide students, school districts, and researchers. (NSF 99-93; http://www.nsf.gov/cgi-bin/get- U.S. Antarctic Program investigators volunteer pub?nsf9993). Operational resources in to include TEA participants in their field par- Antarctica also are used to support scientists ties; NSF selects the teachers competitively. from other Federal agencies. The Antarctic Artists and Writers Program Highlights of this year's austral summer provides opportunities for painters, photogra- research include: phers, writers, and others to use serious writ- ing and the arts to increase understanding of • the first year of the 5-year multi-disciplinary the Antarctic and America's heritage there. The International Trans-Antarctic Expedition, 1999-2000 austral summer includes a novel on which integrates meteorology, remote sens- science and scientists for middle-grade chil- ing, ice coring, glaciology, and geophysics dren; a photographic book; natural sound to learn more about West Antarctica's role recordings; and underwater photography in in the global change McMurdo Sound. • a 52-day Antarctic Pack Ice Seal research Logistics to support these projects cruise to study how changes in the environ- includes heavy-lift, ski-equipped C-130 air- ment cause fluctuations in the abundance, planes operated by the New York Air National growth patterns, life histories, and behavior Guard, ski-equipped Twin Otter airplanes • a study of microbes found in snow samples chartered from a Canadian firm, and C-141 from the South Pole to determine if they are and C-5 air-planes provided by the U.S. Air indigenous to the interior of Antarctica and to Force between New Zealand and McMurdo learn more about their biology and ecology Station. Contract helicopters are headquar- • continued support of the Center for Astro- tered at McMurdo to provide operational physical Research in Antarctica at the geo- and close science support. Ground vehicles graphic South Pole operated and maintained by an NSF contrac- • measuring, monitoring, and studying atmos- tor, provide specialized science support and pheric trace gases associated with the annual other services. Annually, a U.S. Coast Guard depletion of the ozone layer above Antarctica. icebreaker opens a channel to McMurdo and • the third year of drilling and related geolog- provides science support. A tanker and a ical work at Cape Roberts near McMurdo cargo ship, operated by the Military Sealift iii

U.S. ANTARCTIC PROGRAM, 1999-2000 ANTARCTIC U.S. PROGRAM, Command, bring fuel, cargo, and equipment each January. Continuing the modernization and improve- ment of Amundsen-Scott South Pole Station, crews will prepare the foundations for a replacement laboratory that will be built on supports above the icey plateau and will begin the exterior of a new power plant, the interior of which will be completed over the austral winter. The South Pole Safety and Environmental Project (a $25-million undertaking) and the South Pole Station Modernization Project (a $128-million initiative) will replace the existing 24-year-old station by 2005. This book is arranged by scientific discipline, except for sections focused on multi-investigator, multi-disciplinary research projects and a short list of technical projects in the table below. The order reflects the organization of the Antarctic Sciences Section of NSF's Office of Polar Programs, which funds projects in biology, medical research, ocean sciences, climate studies, geology and geophysics, glaciology, aeronomy, astronomy, and astrophysics. Related information products that are produced or funded by NSF include:

• Press releases issued by the Foundation’s Public Affairs Office to describe specific research progress. See the NSF World Wide Web page at http://www.nsf.gov or call 703-306-1070. • Antarctic Journal of the United States review issues, which contain short reports by investigators about research recently performed in Antarctica. These issues are online (http://www.nsf.gov/od/opp/antarct/journal) and are available in print from the Office of Polar Programs ([email protected]). iv

Technical projects supporting the 1999-2000 USAP antarctic field program 1999-2000 ANTARCTIC U.S. PROGRAM,

Project title Project manager, affiliation Polar Ice Coring Office(PICO) Hot-water drilling at the South Pole for Karl Kuivinen, the AMANDA project (TA-150-A) University of Nebraska Karl Kuivinen, PICO ice-core drilling at Siple Dome (TI-150-B) University of Nebraska Automatic Geophysical Observatory (AGO)— Jay Burnside, servicing and installation (TO-296-O) Antarctic Support Associates Steve Currier, Synthetic Aperture Radar project; (TO-308-O) NASA Wallops Flight Facility Robert Whritner, McMurdo Sound Metsat Station— Arctic and Antarctic refurbishment of Terascan satellite reception & Research Center, Scripps processing system at Palmer Station (TO-312-O) Institution of Oceanography Charles Booth, UV-monitoring network (TO-513-O) Biospherical Instruments, Inc.

Artists and Writers Program projects, 1999-2000 U.S. Antarctic Program

Project title Participant Novel for middle-grade children on Lucy Jane Bledsoe, science and scientists (WO-007-O) Berkeley, California Photography book documenting the Stuart Klipper, U.S. Antarctic Program (WO-009-O) Minneapolis, Minnesota Douglas Quinn, Natural sound recordings (WO-004-O) Petaluma, California Underwater photography, Norbert Wu, McMurdo Sound (WO-317-O) Pacific Grove, California v U.S. ANTARCTIC PROGRAM, 1999-2000 ANTARCTIC U.S. PROGRAM, U.S. Antarctic Program, 1999-2000 Sites of major activities

Number of projects to be supported during 1999-2000 1

AERONOMY AND ASTROPHYSICS including a particular interest in the sun AERONOMYASTROPHYSICS AND The polar regions have been called Earth’s and cosmic rays. Astrophysical studies are window to outer space. Originally, this term primarily conducted at Amundsen-Scott applied to aurora and other dynamic events South Pole Station or on long-duration staged as incoming solar plasmas encoun- balloon flights launched from McMurdo. tered the Earth’s geomagnetic fields. Because of its unique properties, the polar Virtually all research projects sponsored upper atmosphere becomes a virtual screen by this program benefit from (indeed most on which the results of such interactions can require) the unique physical conditions found be viewed (and through which evidence of only in the high latitudes, yet their ramifica- other processes can pass). More recently, tions extend far beyond Antarctica. High- this concept has been extended to refer to latitude astrophysical research contributes the “ozone hole” in the polar atmosphere. to the understanding of Antarctica’s role in As scientists have verified an annual loss of global environmental change, promotes inter- ozone in the polar stratosphere, a window disciplinary study of geosphere/biosphere previously thought “closed” (stratified ozone interactions in the middle and upper atmos- blocking the sun’s ultraviolet rays) is now phere, and improves understanding of the known to “open” in certain seasons. critical processes of solar energy in these For astronomers and astrophysicists, the regions. Life exists on earth in a balance – not South Pole presents unique opportunities. only because of the critical distance from the Thanks to the relative lack of environmental sun — but also because of numerous chemi- pollution and anthropogenic “noise,” the cal and atmospheric phenomena peculiar to unique pattern of light and darkness, and the our atmosphere. The 20th century expansion geomagnetic force field properties, scientists of traditional astronomy to the science of staging their instruments here can probe the astrophysics, coupled with the emerging structure of the sun and the universe with discipline of atmospheric science (See also unprecedented precision. Studies supported the Ocean and Climate Systems program), is by the Aeronomy and Astrophysics program nowhere better exemplified than in Antarctica. probe three regions: AMANDA—Antarctic Muon and • The stratosphere and the mesosphere: Neutrino Detector Array. In these lower regions, current research Robert Morse, University of Wisconsin. focuses on stratospheric chemistry and aerosols, particularly those implicated Neutrinos are elementary particles: With no in the ozone cycle. electrical charge, and believed to have very • The thermosphere, the ionosphere, and little or no mass, they can take any of three the magnetosphere: These higher regions forms. Coursing through the universe, they derive many characteristics from the inter- interact only rarely with other particles. play between energetically-charged parti- AMANDA’s primary objective is to discover cles (ionized plasmas in particular) and the sources – both within our galaxy and geomagnetic/geoelectric fields. The upper beyond – of the shower of very-high-energy atmosphere, particularly the ionosphere, neutrinos descending on (and usually pass- is the ultimate sink of solar wind energy ing through) the Earth. transported into the magnetosphere just AMANDA uses an array of photomultiplier above it. This region is energetically tubes embedded between 1 and 2 kilometers dynamic, with resonant wave-particle in the ice near the South Pole to create a interactions, and Joule heating from Cherenkov detector out of the natural ice. currents driven by electric fields. This system will detect high-energy neutrinos • The universe beyond, for astronomical and originating off the planet that have passed astrophysical studies: Many scientific ques- through Earth. Such sources of origin could tions extend outside the magnetosphere, be diffuse, made up of contributions from 2

AERONOMYASTROPHYSICS AND many active galactic nuclei (AGNI); or they energies above approximately 100 teraelec- could be point sources of neutrinos – coming tronvolts. This can be done by analyzing from supernova remnants (SNRs), rapidly coincidences between SPASE and AMAN- rotating pulsars, neutron stars, individual DA. Such coincident events are produced blazars, or other extragalactic point sources. by high energy cosmic-ray showers with Recently, new sources of high-energy trajectories that pass through SPASE (on gamma rays have been discovered, such as the surface) and AMANDA (buried 1.5 to 2 the source Mrk-421 discovered by NASA’s kilometers beneath it). AMANDA detects Compton Gamma-Ray Observatory (CGRO) the high energy, penetrating muons in and Mt. Hopkins Observatory. AMANDA is those same showers for which SPASE designed to study just such objects, which detects the low energy electrons arriving at are believed to emit high-energy neutrinos the surface. This is meaningful because the copiously. To date, neutrino astronomy has ratio of muons to electrons depends on the been limited to the detection of solar neutri- mass of the original primary cosmic ray nos, plus one brief, spectacular burst from nucleus. VULCAN adds two other ratios that the supernova that appeared in the Large also depend on primary mass in readings Magellanic Cloud in February 1987 (SN- from the showers it detects. 1987a). Only now is it becoming technically • To use the coincident events as a tagged feasible to build large neutrino telescopes. beam, which will permit investigation and As one of the first-generation detectors, AMAN- calibration of certain aspects of the AMANDA DA promises to make seminal contributions to response. This project cooperates with the this new branch of neutrino astronomy. University of Leeds in the United Kingdom. (AA-130-O) (AO-109-O)

South Pole Air Shower Experiment–2. Magnetometer data acquisition at Thomas Gaisser, University of Delaware. McMurdo and Amundsen-Scott South Pole Stations. As cosmic rays from space arrive at the Louis Lanzerotti, AT&T Bell Laboratories, and Earth’s upper atmosphere, molecules begin Alan Wolfe, New York City Technical College. to feel the impact. The South Pole Air Shower Experiment-2 (SPASE-2) deploys a sparsely The magnetosphere is that region of space filled array of 120 scintillation detectors over surrounding a celestial object (such as the 15,000 square meters at South Pole. This Earth or the Sun) where the object’s magnetic instrument array detects energetic charged field is strong enough to trap charged parti- particles (primarily electrons) that are produced cles. Magnetometers have been installed at in the upper atmosphere by cosmic rays. To selected sites in both polar regions to meas- detect the Cherenkov radiation produced in the ure changes in the magnitude and direction of high atmosphere by the same showers, a sub- Earth’s magnetic field (in the frequency range array called VULCAN has been constructed of from 0 to about 0.1 hertz). The unique climatic nine photodetectors. The SPASE array is locat- conditions in Antarctica also permit scientists ed less than half a kilometer from the top of to view the atmosphere optically and to corre- AMANDA; this low-energy collector is designed late such hydromagnetic-wave phenomena to complement AMANDA’s neutrino detecting with particle-precipitation measurements. capacity. [Described in the previous project In this project we are measuring such varia- summary (AA-130-O)] tions with magnetometers installed at conju- SPASE-2 has two goals: gate sites in both hemispheres; at McMurdo and Amundsen-Scott South Pole Stations, • To investigate the high-energy primary cos- Antarctica, and at Iqaluit, in the Northwest mic radiation, by determining the relative Territories in Canada. Our data are also being contribution of different groups of nuclei at analyzed and associated with similar data 3

acquired from several automatic geophysical Antarctic auroral imaging. AERONOMYASTROPHYSICS AND observatories comprising the PENGUIN program Stephen Mende, Lockheed Palo Alto [polar experiment network for geophysical Research Laboratory. upper-atmosphere investigations, (AO-112-O)]. Using all of these systems, we are deriving Scientists are only beginning to try to perform information about the causes and propaga- quantitative studies on the dynamic behavior tion of low-frequency hydromagnetic waves of the magnetosphere. In the past, detail-ori- in the magnetosphere, as well as the cou- ented explorations by space satellites have pling of the interplanetary medium into the enabled them to map the average distribution dayside magnetosphere. of magnetospheric energetic particle plasma (AO-101-O) content. But the dynamics of auroral phenomena – when particles from the magnetosphere An investigation of magnetospheric precipitate into the atmosphere, producing boundaries using ground-based fluorescence – have been hard to quantify induction magnetometers operated through optical means. Amundsen-Scott at manned stations as part of an South Pole Station is uniquely situated to observe aurora because the darkness of polar extensive ground array. winter permits continuous optical monitoring; Roger Arnoldy, University of New Hampshire. in most other sites, the sky becomes too bright near local mid-day. The poles of the Earth – the points marking The aurora can actually be regarded as the axis around which the planet rotates – a two-dimensional projection of the three- experience unique magnetic phenomena. dimensional magnetosphere because parti- By measuring magnetic pulsations at these cles tend to travel along the magnetic field high geomagnetic latitudes, scientists can line. By observing the dynamics and the study the plasma physics of some of the morphology of the aurora, scientists get a important boundaries of the magnetosphere. reliable glimpse into the dynamics of the Geophysicists refer to the continuous stream region of the three-dimensional magnetos- of highly-charged particles emitted by the phere associated directly with it. This Sun as the solar wind. Two of the important method relies on knowledge relating the type areas of the magnetosphere are the area of aurora to specific energies of precipitation through which the solar wind enters and the and to specific regions of the magnetosphere. area where its energy is transferred to the In this study, an intensified optical, all-sky Earth’s atmosphere in the form of aurora and imager, operating in two parallel wavelength similar phenomena. channels – 4,278 and 6,300 Ångstroms – will This study employs an array of induction-coil be used to record digital and video images of magnetometers located at high geomagnetic aurora. These wavelength bands allow us to latitudes in both north and south polar regions; discriminate between more- and less-energetic in the Arctic at Sondre Stromfjord, Greenland, electron auroras and other precipitation. The and Iqaluit, Northwest Territories, Canada, and South Pole Station observations of the polar in the Antarctic at Amundsen-Scott South Pole cap and cleft regions entail measuring auroral- and McMurdo Stations. The data collected here precipitation patterns and then interpreting is also being analyzed in the context of that the results in terms of the coordinated obser- from similar magnetometers in the U.S. and vations of (magnetic) radio-wave absorption British automatic geophysical observatory images as well as (high-frequency) coherent- (AGO) networks and the MACCS array in scatter radar measurements. Canada. (The project is jointly supported by This work should provide insight into the the U.S. Arctic and Antarctic Programs.) sources and energization mechanisms of (AO-102-O) 4

AERONOMYASTROPHYSICS AND auroral particles in the magnetosphere, as very-low-frequency (VLF) radio receivers well as other forms of energy inputs into the at Palmer Station, Antarctica, operated in high-latitude atmosphere. collaboration with the British and Brazilian (AO-104-O) Antarctic Programs, both of which operate similar receivers. All are contributors to the A study of very high latitude Global Change Initiative. geomagnetic phenomena. The VLF receivers measure changes in the Vladimir Papitashvili, University of Michigan. amplitude and phase of signals received from several distant VLF transmitters. These changes This project continues a joint U.S./Russian follow lightning strokes because radio (whistler) program to operate an Antarctica-based waves from the lightning can cause very ener- array of automated magnetometers. As the getic electrons from the Van Allen radiation only land mass at very high latitudes, the belts to precipitate into the upper atmosphere. antarctic continent is uniquely suited to This particle precipitation then increases ioniza- these instruments, providing an excellent tion in the ionosphere, through which the prop- and stable location for magnetometric agating VLF radio waves must travel. Because investigations of the polar cap current the orientations to the VLF transmitters are systems in the Earth’s magnetosphere. known, it is possible to triangulate the lightning Such studies are particularly important sources that caused the changes, and thus to to the understanding of how the energy and track remotely the path of the thunderstorms. momentum from the solar wind becomes (AO-106-O) coupled to the magnetosphere, ionosphere, and upper atmosphere. They also provide Study of polar stratospheric clouds an excellent point of reference for other by lidar. satellite-based experiments (both currently Guido Di Donfrancesco, Instituto De Fisica in progress and planned for the near future). Dell’Atmosfere, Rome, Italy. The specific tasks to be undertaken include design improvements in the digital geomag- The appearance each spring of the stratos- netic data-acquisition systems at Vostok and pheric ozone hole above Antarctica is driven Mirnyy, as well as continued operation and by chlorine compounds interacting on the sur- maintenance of autonomous stations along faces of polar stratospheric clouds (PSCs) that the Russian traverse route to Vostok. One formed the previous polar winter. This is one aspect of the study that should enhance our explanation for why ozone depletion is much results is the new satellite data-transmission more severe in polar regions than elsewhere. capability at Vostok. This will provide a near- This project uses light detection and range real-time polar cap magnetic index for space, finding (lidar) to study the polar stratospheric weather and research applications. clouds (PSCs), stratospheric aerosol, and the (AO-105-O) thermal behavior and dynamics of the atmosphere above McMurdo Station. Continuous Global thunderstorm activity and its lidar observations provide insight on PSC for- effects on the radiation belts and the mation, evolution, and other peculiar charac- lower ionosphere. teristics. These data will provide a complement to the information gained from balloon- Umran Inan, Stanford University. borne instruments in project AO-131-O, and thus collaborative activities will be coordinat- Tracking dynamic storms is a challenge, but ed with the University of Wyoming. lightning associated with thunderstorms can (AO-107-O) provide scientists an indirect way of monitoring global weather. This project employs 5

Extremely-low-frequency/ rents at predictable heights. Hydroxyl radicals AERONOMYASTROPHYSICS AND very-low-frequency (ELF/VLF) (OH), for example, are confined to a fairly nar- waves at the South Pole. row band near 90 kilometers altitude. This study uses a Fabry-Perot infrared inter- Umran S. Inan, Stanford University. ferometer (located at Amundsen-Scott South Pole Station, Antarctica) to make orthogonal Atmospheric scientists orient their studies observations of the band spectra of several around different strata, or regions, and the trace species – most importantly the hydroxyl boundaries and interactions between these radical (OH). The doppler shift of the band regions are of particular interest. How are the lines provides an algorithm for researchers to upper atmospheric regions coupled electro- measure the windspeed. The brightness and dynamically? What can we learn by measuring line ratios within the bands provide density the energy that is being transported between and temperature information. the magnetosphere and the ionosphere? (AO-110-O) These are but two of the questions the U.S. Antarctic Program’s automatic geophysical observatory program is designed to explore. Riometry in Antarctica and conjugate Plasmas occur in the magnetosphere and regions. the ionosphere, and can be transported and Theodore J. Rosenberg and Allan T. Weatherwax, accelerated by a variety of different wave- University of Maryland at College Park. particle interactions. One important dynamic in this system is particle precipitation that The University of Maryland continues to is driven by extra-low-frequency/very-low- conduct research into upper atmospheric frequency (ELF/VLF) waves. Thus, measuring processes; using photometry to take auroral ELF/VLF waves from multiple sites provides luminosity measurements and riometry to a powerful tool for remote observations of make high-frequency cosmic noise absorp- magnetosphere processes. tion measurements. A primary focus of our This project maintains a system at Amundsen- analysis activities over the next several years Scott South Pole Station to measure magnetos- will include coordinated ground- and satellite- pheric ELF/VLF phenomena, and to correlate the based studies and Sun-Earth comparisons. data with measurements made by the automat- The latest work also involves extensive ic geophysical observatory system. collaboration with other investigators using (AO-108-O) complementary data sets. Continuation of science activities into the 1998-2001 time High-latitude antarctic neutral frame will enable us to participate in, and mesospheric and thermospheric contribute to, several major science initia- tives, including the GEM, CEDAR, ISTP/GGS, dynamics and thermodynamics. and National Space Weather programs as Gonzalo Hernandez, University of we enter the next solar maximum period. Washington. Riometers measure the relative opacity of the ionosphere. This work employs a new imaging The antarctic region attracts atmospheric riometer system called IRIS (imaging riometer scientists for a number of reasons; a basic for ionospheric studies). The first two IRISs one is that measurements taken at the Earth’s were installed at Amundsen-Scott South Pole rotational axis are largely unaffected by plan- Station and Sondre Stromfjord, Greenland. etary magnetic waves. This simplifies the study A third IRIS has been installed at Iqiluit, of the large-scale dynamics of the atmosphere. Northwest Territories, Canada – the magnetic For example, how do scientists measure conjugate to South Pole. Broadbeam riometers the temperature and windspeed of the atmos- also operate at several frequencies at South phere? One primary method is by deduction, Pole, McMurdo, and Iqiluit; auroral photome- based on the emission spectra of certain ters operate at South Pole and McMurdo. This trace gases as they are borne along in cur- 6

AERONOMYASTROPHYSICS AND array of instruments constitutes a unique net- and in cooperation with conjugate studies work for the simultaneous study of auroral performed in the Northern Hemisphere. effects in both magnetic hemispheres. (AO-112-O) The focus of all of this work is to enhance understanding of the relevant physical All-sky-camera measurements of the processes and forces that drive the observed aurora australis from Amundsen-Scott phenomena; this includes both internal (such South Pole Station. as magnetospheric/ionospheric instabilities) Masaki Ejiri, National Institute of Polar and external forces, such as solar wind/IMF Research, Japan. variations. From such knowledge may emerge an enhanced capability to forecast; many Amundsen-Scott South Pole Station, located atmospheric events can have negative tech- at the south geographic pole, is a unique nological or societal impact, and accurate platform from which to undertake measure- forecasting could ameliorate these impacts. ments of the polar ionosphere, situated in (AO-111-O) such a way that dayside auroras can be viewed for several hours each day. Research Polar experiment network for geo- has shown these auroras come from the pre- physical upper-atmosphere investi- cipitation of low-energy particles entering gations (PENGUIN). the magnetosphere in the solar wind. Theodore Rosenberg, University of Maryland Since 1965, data have been acquired at the at College Park. South Pole using a film-based, all-sky-camera system. Using advanced technology, we can The data obtained from automatic geophysi- now digitize photographic images and process cal observatories (AGOs) help researchers large amounts of information automatically. understand the Sun’s influence on the struc- As this project continues to acquire 35-mil- ture and dynamics of the Earth’s upper limeter photographic images, American and atmosphere. The ultimate objective of this Japanese researchers will collaborate in research into how the solar wind couples deploying a new all-sky-camera processing with the Earth’s magnetosphere, ionosphere, system developed at Japan’s National Institute and thermosphere is to be able to predict of Polar Research. This system displays data solar-terrestrial interactions that can inter- in a geophysical coordinate framework, and fere with long-distance phone lines, power analyzes series of images over short and long grids, and satellite communications. intervals thus enhancing observations over A consortium of U.S. and Japanese scien- discrete, individual photographs. tists will use a network of six AGOs, estab- These studies should provide further lished on the east antarctic polar plateau and insight into the physics of the magnetos- equipped with suites of instruments to meas- phere, the convection of plasma in the polar ure magnetic, auroral, and radiowave phe- cap, and solar winds in the thermosphere; nomena. The AGOs are totally autonomous, specifically dayside auroral structure, night- operate year round and require only annual side substorm effects, and polar-cap arcs. austral summer service visits. (AO-117-O) When combined with measurements made at select manned stations, these arrays facilitate Solar and heliosphere studies with studies on the energetics and dynamics of the antarctic cosmic-ray observations. high-latitude magnetosphere on both large and John Bieber, University of Delaware. small scales. The research will be carried out along with in situ observations of the geospace Cosmic rays – penetrating atomic nuclei from environment by spacecraft, in close coopera- outer space that move at nearly the speed of tion with other nations working in Antarctica light – continuously bombard the Earth. 7

Neutron monitors deployed in Antarctica pro- Type 1 PSCs depolarize incident radiation. AERONOMYASTROPHYSICS AND vide a vital three-dimensional perspective on Because the laser transmitters in AGO lidar this shower and how it varies along all three produce light that is highly linearly polarized, axes. Accumulated neutron-monitor records they can generate a depolarization signal of (begun in 1960 at McMurdo Station and in up to several percent. These data are stored 1964 at South Pole Station) provide a long- in the lidar instruments and, at least once a term historical record that supports efforts to day, AGO lidar transmits an atmospheric pro- understand the nature and causes of cosmic- file back to NASA’s Goddard Space Flight ray and solar-terrestrial variations occurring Center in Greenbelt, Maryland. over the 11-year sunspot cycle, the 22-year This project also conducts continuous, Hale cycle, and even longer timescales. long-term monitoring of atmospheric trans- This project continues a series of year-round mission and backscatter from the surface. observations at McMurdo and Amundsen- These data are being compiled for use by the Scott South Pole Stations, recording cosmic Geoscience Laser Altimeter System (GLAS), rays with energies in excess of 1 billion elec- which produces specialized information on tronvolts. These data will advance our under- atmospheric conditions. standing of a number of fundamental plasma (AO-126-O) processes occurring on the Sun and in interplanetary space. At the other extreme, we will Rayleigh and sodium lidar studies of study high time-resolution (10-second) cos- the troposphere, stratosphere, and mic-ray data to determine the three-dimen- mesosphere at the Amundsen-Scott sional structure of turbulence in space, and to elucidate the mechanism by which energetic South Pole Station. charged particles scatter in this turbulence. George Papen, University of Illinois. (AO-120-O) The Earth’s atmosphere is described by sever- Rayleigh and sodium lidar studies of al stratified layers, each with distinctive structure, dynamics and characteristics. The strat- the troposphere, stratosphere, and osphere begins about 11 kilometers (km) mesosphere at McMurdo and above the surface; the mesosphere runs from Amundsen-Scott South Pole Stations. about 50 km to its upper boundary, the Jim Abshire, National Aeronautics and Space menopause, where atmospheric temperature Administration, Goddard Space Flight Center. reaches its lowest point (about –80°C), before beginning to rise with increasing altitude Each austral winter, polar stratospheric through the outer layer, the thermosphere, clouds (PSCs) form in the extremely cold which runs from 80 km to outer space. polar stratosphere. Each spring, as the This research deploys a sodium-resonance stratospheric ozone begins to degrade, one lidar at the South Pole to study the atmos- particular form of these PSCs, the Type 1, phere’s vertical structure and dynamics, from appear to have a particular role. This project’s the lower stratosphere up to the menopause. primary science mission is to detect, monitor As the project enters its third year, scientists and profile these Type 1 PSCs with the auto- will add an iron-resonance lidar, extending mated geophysical observatory (AGO) lidar. their ability to measure the air dynamics and This is an ongoing, National Aeronautics and temperature structure even higher, to about Space Administration (NASA)-funded project 100 kilometers. Another addition, an airglow to develop and demonstrate a compact, low- imaging camera, will be used to study hori- power, and autonomous atmospheric lidar zontal structure. system for operation throughout the AGOs This final complement of instrumentation, that have been established in Antarctica by used in conjunction with the normal balloon- the U.S. Antarctic Program. borne radiosondes flown regularly from South Pole, will provide extensive data on: 8

AERONOMYASTROPHYSICS AND • the temperature structure from the surface Station, in three U.S. automatic geophysical to 100 kilometers altitude; observatories and in two British automatic • the nature of the polar stratospheric geophysical observatories. clouds (PSCs), which are important to (AO-128-O) ozone chemistry; • the variability and frequency of occurrence In situ measurements of polar of metallic layers in the mesosphere, which stratospheric clouds spanning the play roles in communications as well as austral winter and of ozone from late atmospheric chemistry; • atmospheric gravity waves; and winter to early spring. • many other phenomena, some of which are Terry Deshler, University of Wyoming. unique to the South Pole. (AO-127-O) The appearance each spring of the stratospheric ozone hole above Antarctica is driven High-latitude electromagnetic wave by chlorine compounds interacting on the surfaces of polar stratospheric clouds (PSCs) that studies using antarctic automatic formed the previous polar winter. This is one geophysical observatories. explanation for why ozone depletion is much James LaBelle, Dartmouth College. more severe in polar regions than elsewhere. This project uses balloon-borne instru- Aurora are light shows (streamers and arches ments to provide detailed information on the of light) created when electrons accelerated clouds’ particles, their distribution, and on along Earth’s magnetic field lines excite ozone changes. Our measurements will pro- atoms in the atmosphere; they occur at the vide vertical profiles of both the PSCs and poles because of the peculiar magnetic flux ozone, size distributions of the PSC particles, generated there. The energy associated with and some information on their composition this phenomenon is significant and complex; and physical state (liquid or solid). Our proj- one small but distinctive aspect of that ener- ect is enhanced by a lidar system at McMurdo gy are radio emissions detectable at frequen- Station operated by the Instituto De Fisica cies between 0.05 and 5.0 megahertz (MHz). Dell’Atmosfere [(Rome), see project AO-107- Scientists understand the phenomenon of O]. The results contribute to the World auroral hiss that causes broadband noise at Meteorological Organization/UNEP Network frequencies below 1 MHz. But two other radio for the Detection of Stratospheric Change as phenomena attributable to auroras remain well as to the Global Change Initiative. unexplained: Narrowband emissions near 2.8 (AO-131-O) and 4.2 MHz, and broadband noise bursts in the frequency range of 1.4 to 4.0 MHz. Trace gas measurements over the Although these radio emissions constitute South Pole using millimeter-wave a small fraction of the total energy of the aurora, they may provide important clues to spectroscopy. the more energetic processes; this possibility Robert L. de Zafra, State University of New would mirror the use of radio emissions from York at Stony Brook. the Sun to infer processes taking place in the solar corona. Many atmospheric gases radiate millimeter- Taking advantage of radio-quiet antarctic length radio waves, but each species has its conditions, this project uses low-frequen- own unique spectrum. These fingerprints not cy/middle-frequency/high-frequency only identify the gas, but also provide informa- receivers in hopes of developing insights tion on its temperature and pressure. These about these emissions from antarctic auroral properties enable scientists to use the millime- zone and polar cap sites. The receivers will ter-wave spectrum of the atmosphere to deter- be installed at Amundsen-Scott South Pole mine how abundantly and at what altitudes a number of trace species can be found. 9

This research uses a millimeter spectro- these events face several hurdles: The Sun AERONOMYASTROPHYSICS AND scope to monitor the atmosphere above must be observed for long, continual periods, South Pole, Antarctica, for ozone, carbon but the Earth’s rotation limits unbroken monoxide, nitrous oxide, nitric acid, water observation from any fixed telescope to the vapor, and nitrogen dioxide, over the course length of a day; further, the required resolu- of a year. Several of these gases have impor- tion can be achieved only by a telescope situ- tant roles in the formation of the annual ated above most of the atmosphere. Thus far, antarctic ozone hole. Others – particularly only two solutions have been found. You can water vapor and carbon monoxide – can pro- build a large, special purpose spacecraft for vide information about the vertical transport hundreds of millions of dollars, or launch a and other dynamics of the upper strato- long distance balloon (LDB) from a polar site. sphere and the mesosphere. This study, The Flare Genesis Experiment, (AO-138-O) uses a high-altitude, long-duration balloon fly- ing around the antarctic continent to deploy an Cosmology from Dome-C in 80-centimeter telescope that captures images Antarctica. and magnetograms of the solar photosphere Lucio Piccirillo, Bartol Research Institute, and chromosphere; this instrument produces University of Delaware. an unprecedented resolution of 0.2 arc-sec. The project is jointly sponsored by the National When the universe was created some 15 billion Science Foundation, the National Aeronautics years ago in the Big Bang, matter began cours- and Space Administration, and the Air Force. ing outward. The general flux of that move- (AB-146-O) ment was discovered in 1965, and is known as thermal cosmic microwave background radia- Center for Astrophysical Research in tion (CMBR). Measurements of the CMBR pro- Antarctica (CARA). vide the only direct evidence on the distribu- Stephan Meyer, University of Chicago. tion of matter in the very early Universe. Concordia is one of the highest and coldest Astronomers probe the infrared (IR) spec- sites presently occupied in Antarctica. These trum at submillimeter scales in search of conditions minimize water vapor in the atmos- data that could suggest answers to some of phere, which can hinder accurate measure- the seminal questions about the formation of ments of the CMBR, which is anisotropic; that the Universe; such as: is, its readings vary along the different axes. Thus the new French/Italian station on Dome C • How do stars form from interstellar gas? in Antarctica (Concordia Station) is a potential- • How did the planets form? ly superb place from which to make anisotrop- • What was the nature of primeval galaxies? ic CMBR measurements. This project involves • How were matter and energy distributed an international collaboration between the in the early Universe? United States, Italy, and France. We will also evaluate the site for other future uses. Antarctica is an ideal spot for such (AO-140-O) research: The cold temperatures and lack of water vapor in the atmosphere above the An optical investigation of the polar plateau makes the infrared spectrum of genesis of solar activity. sky in that region consistently clearer and David M. Rust, Johns Hopkins University. darker than anywhere else on Earth. These conditions enable scientists to collect meas- Energy stored in the Sun’s magnetic fields is urements that would be extremely difficult or released in a number of dynamic phenomena, impossible from other sites. such as flares and coronal mass ejections. To capitalize on these advantages, the Scientists trying to model and understand University of Chicago and several collaborating 10

AERONOMYASTROPHYSICS AND institutions in 1991 established the Center for ports a number of other efforts including Astrophysical Research in Antarctica (CARA), wide-field cameras, a near-IR sky brightness one of 23 Science and Technology Centers monitor (in collaboration with the University funded by the National Science Foundation. of New South Wales), and an instrument for CARA’s scientific mission is to investigate the monitoring mid-IR sky brightness and trans- conditions for astronomy at the South Pole mission (in collaboration with the National and other sites on the polar plateau, and to Aeronautics and Space Administration’s establish an observatory at the South Pole. Goddard Space Flight Center). Currently, CARA supports research using three Bob Lowenstein, University of Chicago. major telescope facilities: (AC-372-O)

• The Astronomical Submillimeter The Degree Angular Scale Interferometer Telescope/Remote Observatory (AST/RO) (DASI) is a 13-element interferometer project uses a 1.7-meter (m) diameter tele- designed to measure anisotropies in the scope to survey interstellar gas in the Cosmic Microwave Background (CMB). Now in galactic plane, the galactic center, and the its final phase of construction, DASI will cap- Magellanic Clouds. ture radiation readings over a large range of • The South Pole Infrared Explorer (SPIREX) scales with very high sensitivity, and should project uses a 0.6-m diameter telescope to be collecting data by Feb 2000. The instru- observe distant galaxies, cool stars, and ment uses cooled HEMT amplifiers running heavily obscured star-forming regions. between 26 and 36GHz, in five 2-GHz chan- • The Cosmic Background Radiation nels and will operate from the South Pole. Anisotropy (COBRA) project helps John Carlstrom, University of Chicago. researchers test current theories of the (AC-373-O) origin of the Universe. The South Pole Infrared Explorer (SPIREX) In addition to projects using these three project is ideal for extensive large-scale telescopes, CARA’s Advanced Telescopes infrared and submillimeter surveys of star- Project collects data on the quality of polar forming regions in the Milky Way and plateau sites for astronomical observations, Magellanic Clouds. The SPIREX telescope (60 and configures plans for future telescopes centimeters in diameter) was built to exploit and facilities. The following projects and prin- the unique observing conditions at the South cipal investigators are currently part of CARA: Pole and to develop and demonstrate the technology needed to operate IR telescopes CARA-wide operations and activities. during the antarctic winter. Stephan Meyer, University of Chicago. The telescope has been enhanced to lower (AC-370-O) total telescope emissivity to just 5 percent. The Abu camera is based on an Aladdin The Antarctic Submillimeter Telescope and 1024x1024 pixel indium antimonide focal Remote Observatory (AST/RO) project devel- plane array and a set of broad- and narrow- ops studies on atomic and molecular gas in band filters spanning the range between 2.4 the Milky Way and nearby galaxies. Proposals and 5 millimeter (mm). It was developed at to use their 1.7-m diameter telescope are NOAO to test advanced focal-plane arrays. invited from the astronomical community. Combining this camera with the telescope Antony Stark, Smithsonian Institution. permits wide-field (10.2 arc-minutes) astro- (AC-371-O) nomical imaging at wavelengths of 3-5 microns (µ); this region of the spectrum is The Advanced Telescopes Project (in addition where the advantages of the South Pole over to gathering measurements of “seeing” qual- temperate sites are greatest. ity using the SPIREX telescope) also sup- 11

The Abu/SPIREX project is the result of array designed for other telescopes; but AERONOMYASTROPHYSICS AND unique collaboration: The National Optical those instruments (for example, at the Astronomy Observatories (NOAO) contributes Caltech Submillimeter Observatory and the the Abu, the best existing 3-5 micron camera; Owens Valley Radio Observatory) provide the United States Naval Observatory (USNO) much better angular resolution. SPARO’s and CARA commit to operating the SPIREX and geographic advantage, however, results in conducting the science at the world’s darkest a much enhanced submillimeter sensitivity 3-5 micron site, the South Pole. In addition to extended emission. to researchers at NOAO and USNO, the effort The primary goal for the 1999-2000 phase includes collaborators from Boston University of the project is to reveal the large-scale (BU), Goddard Space Flight Center (GSFC), magnetic field in the nucleus of our Galaxy. Ohio State University (OSU), Rochester Giles Novak, Northwestern University. Institute of Technology (RIT), the University of (AC-376-O) Chicago (UC), the University of New South Wales (UNSW), and the Universities Space Research Association (USRA). Bob Lowenstein, University of Chicago. (AC-374-O)

The Viper telescope is a 2-meter class telescope that will extend the observations (now being made with the 0.75-meter Python telescope) to structures in the cosmic microwave background having smaller angular scales. The primary goal of the Viper project is to determine the power spectrum of the CMBR anisotropy over the range of angular scales where cosmological models most differ in their predictions. Viper data should permit scientists to better discriminate among these models. Viper images will also be used to search for cosmological defect-imprints on the CMBR. Jeffrey Peterson, Carnegie-Mellon University. (AC-375-O)

The Submillimeter Polarimeter for Antarctic Remote Observing (SPARO), operating on the Viper 2-meter telescope is newly deployed to the Pole in 1999. SPARO is a 9-pixel, 450-micron polarimetric imager, which requires only infrequent cryogen refills, making maintenance easier during the winterover. The South Pole offers superb conditions for SPARO observations, extending submillimeter polarimetry (measurement of the polarization of thermal emission from mag- netically aligned dust grains) to regions of low-column density that cannot be studied from other sites. SPARO is similar to polarimeters in the University of Chicago 12

BIOLOGY AND MEDICINE AND BIOLOGY ANTARCTIC BIOLOGY AND MEDICINE prey and on primary production; and the The Biology and Medicine program funds role of marine phytoplankton in carbon research to improve understanding of antarc- dioxide cycling. tic life forms and ecosystems – their physiolo- • Terrestrial and limnetic ecosystems: gy, behavior, adaptations, and relationships. Organisms in ice-free areas and in perenni- Projects range across all organizational levels ally ice-covered lakes show remarkable – from the molecule, cell and organism to adaptations to extreme environments. relationships within communities and ecosys- Relatively few species thrive here, which tems, to the level of global processes. This is facilitates the study of ecosystem dynam- another area of inquiry where scientific goals ics and the interpretation of experiments, extend far beyond learning (in this field, although much more remains to be learned about flora and fauna) in the high latitudes. about adaptive mechanisms and evolution- Antarctica is a place like no other: as an ary processes. intriguing habitat, a scientist’s dream; a land • Population biology and physiological ecol- where water is scarce – truly a desert – ogy: At the next level, looking at relation- despite containing more than two-thirds ships among organisms, studies have of the world’s freshwater supply trapped in focused on the variability and dynamics of the ice. Though it borders the world’s major populations of krill and other zooplankton; oceans, the Southern Ocean system is ecological relationships among and unique in the world, a sea where average between fish species, marine mammals, temperatures don’t reach 2°C in summer, and birds have also been the object of where even the water itself is so unique that much research, with many issues still to it can be identified thousands of miles away be further explored. As organized pro- in currents that originated here. As the Earth grams of antarctic science enter their fifth makes its elliptical journey around the sun decade (some even longer), data sets and each year – tilted on its rotational axis – the ongoing observations are elucidating sun “sets” in April, not to be seen again until manmade as well as natural changes. September. And the ice – unimaginable, • Adaptation: Antarctic extremes present a incomparable vastness of ice – in a dozen fundamental research opportunity; topics different varieties, at times and in places sev- include low-temperature photosynthesis eral thousand meters thick, two major ice and respiration, enzymatic adaptations and sheets (the East larger than most countries), adaptive physiology such as the development changing dynamically all the time. in fish of antifreeze compounds and modi- Adaptations and behavior developed in fications to the circulatory system in seals; response to these extreme conditions provide also continuing interest in the response of insight into the intricacies (as well as the fun- (and impacts upon) organisms to increased damental processes) of evolution. These UV-B radiation from the ozone hole. extremes have also driven the development of • Human behavior and medical research: ecosystems simple enough to reveal wonder- Antarctica’s extreme climate and terrain fully clear pieces of the web of life on Earth. impose a quite spartan and unconvention- Support is focused on the following areas: al existence upon scientists and others who live and work there. As people are • Marine ecosystem dynamics: Among the subjected to social, psychological, and research topics are understanding the nat- physiological stresses (exacerbated during ural variability of marine ecosystems; cor- the winter isolation) research opportuni- relating the structure and function of the ties arise. Studies focus on epidemiology, marginal ice-zone ecosystem with oceanic thermal regulation, immune system func- and atmospheric processes; exploring the tion, individual behavior, and group sources of nutrition and their influence on dynamics. 13

Life in Extreme Environments Role of antifreeze proteins in MEDICINE AND BIOLOGY (LEXEN): Biology and ecology of freezing avoidance in antarctic South Pole snow microbes. fishes: Ecological and organismal Edward J. Carpenter, State University of New physiology, structure-function and York at Stony Brook. mechanism, genetics, and evolution. Arthur DeVries, University of Illinois. Scientists have always portrayed Antarctica’s interior ice sheets as a region extremely hos- Despite temperatures that can dip below 0°C, tile to life. As arid as the world’s severest antarctic waters provide a life-sustaining envi- desert, the heart of the continent has no water ronment for a number of fishes. Thus a basic (H2O as a liquid), relentlessly low tempera- question: Why don’t these fish freeze when tures and long periods with minimal solar they take this water in through their gills? One energy (darkness) – all conditions that under- primary reason seems to be the presence of mine the viability of indigenous organisms. biological molecules that work like antifreeze Move toward the fringes of the continent in an engine, so-called antifreeze glycopep- where these conditions moderate somewhat, tides (AFGPs) and antifreeze peptides (AFPs). and this picture begins to change, with numer- By devising experiments that distinguish a ous species of plants, protozoa, and bacteria. number of factors, this project probes some In snow samples collected in January 1997 interesting questions about how these fishes near the Amundsen-Scott South Pole Station, may have developed such systems. however, scientists have found microbes that How much ice – and as an adaptative contain two of the basics of biological life: DNA response, how much “antifreeze” – is found in and pigments that result from photosynthesis. fish from more and less severe environments? The snow was flown immediately to the Crary Researchers will examine how much exogenous Laboratory at McMurdo Station, melted and (imported into the body) and endogenous examined by epifluorescent microscope. Based (manufactured inside the body) ice is found on their shape and fluorescence signatures, in fishes from two distinct environments. The the particles appear to be cyanobacteria. McMurdo area fishes live in the coldest and Subsequent analysis using fluorescent DNA most ice-laden waters of the antarctic region, stains and scanning electron microscopy con- while those living near the Antarctic Peninsula firmed the presence of DNA-containing face a less severe marine environment. Studies microbes with this same shape. will correlate the freezing extremes and com- Formerly known as blue-green algae, pare the circulating levels of AFGPs in the fishes cyanobacteria are now considered to be found in these two environments. Monera: Ancient, often unicellular organisms Other ongoing and new experiments will that lack cell nuclei but which are basic to look for answers to a number of interesting the carbon and nitrogen cycles, as many of and related questions: How does the fish them have photosynthetic properties. organism respond to ice created inside the Are these microbes indigenous to the antarc- body? The antifreeze proteins: How do they tic interior? What can be learned about their function, what is their structure, how do their biology and ecology? These questions will drive molecules actually adhere to the potential this research project, since the discovery of ice to inhibit its growth? What about the organisms capable of surviving in Antarctica’s genes that code for these proteins: What is interior should provide us with new insight into their structure; how are they organized; how how life forms can adapt to conditions previ- might they have evolved? In what tissues in ously believed incapable of supporting life. the fish’s body is the AFGP gene expressed? The biomolecules and metabolism of these (BO-005-M) creatures must be unique, and could prove valuable for molecular engineering research. (BO-004-O) 14

BIOLOGY AND MEDICINE AND BIOLOGY Use of a long-term database and Weddell seal foraging: Behavioral molecular genetic techniques to and energetic strategies for hunting examine the behavioral ecology beneath the antarctic fast ice. and dynamics of Weddell seal Randall Davis, Texas A&M University at (Leptonychotes weddellii) population. Galveston. Donald B. Siniff, University of Minnesota- Twin Cities. Weddell seals, as carnivorous mammals, hunt underwater but breathe air. To thrive in The Weddell seal (Leptonychotes weddellii) is their aquatic environment, they have devel- found in regions of pack ice or fast ice close to oped some remarkable adaptations. Foraging the antarctic continent. These seals are relative- efficiently deep beneath the extensive, ly long-lived, and the waters of McMurdo Sound unbroken fast-ice along the antarctic coast have provided a continuous environment in requires that they hold their breath for 20 which to study their survival and aquatic repro- minutes or longer (a feat comparable to a ductive patterns. A series of long-term popula- lion or other large terrestrial predator hold- tion studies, ongoing since the mid-1960s, have ing its breath while it locates, pursues, and generated a rare and valuable set of data. captures its prey). Then at the end of a dive, Recently developed molecular biology tech- to avoid drowning, the seals must either niques, however, permit scientists to examine return to the same hole or know the location the DNA of individual seals as well as groups, of other breathing holes. and to gain insight into their genetic histories, What enables Weddell seals to live this breeding systems and reproductive fitness. remarkable life? Until now, detailed investiga- Breeding males behave characteristically; tion of the foraging behavior of marine mam- looking at this behavioral ecology and their mals has not been feasible. Working from an mating systems through the lens of their DNA isolated ice hole in McMurdo Sound, can project backwards in time and correlate Antarctica, this study will employ a small video their reproductive success and the effective system and data logger (attached to the seals’ size of their populations. backs) to analyze their behavior and measure Using and building on the long-term data their consumption of oxygen during voluntary set, the study will also examine how hypothe- dives. We will measure the underwater behav- ses can be tested and parameters can be esti- ior, locomotor performance (swimming velocity, mated, in producing models and studies of stroke frequency and amplitude, and three- population demographics. The population dimensional movements), and energy metabo- dynamics of the Weddell seal will also be lism of Weddell seals during their foraging explored though the lens of immigration and dives. We will test hypotheses on: General emigration into and out of the group. foraging strategies; the general behavior of As the southernmost breeding mammal in “searching,” as well as the mechanics; modes the world, the Weddell seal exemplifies the of swimming; the metabolic price of foraging; ability to adapt to environmental extremes. and how foraging efficiency varies, under dif- Understanding the mating strategies these ferent environmental conditions, and in pursuit seals employ should contribute to a deeper of different types of prey. understanding of the evolution and popula- Effective inquiry into foraging ecology in tion dynamics of the Pinnipedia (a suborder marine mammals requires these sorts of pio- of aquatic, carnivorous mammals, including neering studies, focused on type of prey, all the seals and walruses), as well as how energetics, and foraging behavior. Of all of marine mammals (more generally) compete. the deep-diving Pinnipedae (other species of (BO-009-O) seal and also of walruses), the Weddell seal may provide the best opportunity to advance 15

knowledge of foraging ecology; because: We The program should advance our under- MEDICINE AND BIOLOGY have data on their diving ability; the isolated- standing of the evolution of chemical defens- ice-hole protocol in McMurdo Sound enables es in general, as well as the nature and role recorders to be attached and recovered reli- of bioactive agents in the specific ecology ably; and, when placed in the isolated ice of antarctic marine benthos (organisms living hole, the seals make daily foraging dives. at the bottom of, or in very deep, marine (BO-017-O) environments). (BO-022-O) The chemical ecology of shallow- water marine macroalgae and inver- The biogeochemistry of dimethylsul- tebrates on the Antarctic Peninsula. fide (DMS) and related compounds in James B. McClintock and Charles D. Amsler, a chemically stratified antarctic lake. U. of Alabama, Birmingham. John C Priscu, Montana State University, and Giacomo R. DiTullio, Grice Marine Laboratory, In a number of plant species, evolution has University of Charleston. adapted the basic strategy of developing chemical substances designed to defend The Earth’s atmospheric cycle involves contin- the organism. One general group of these uous transport of basic elements, one of which substances are classified as defensive sec- is sulfur. Dimethylsulfide (DMS) is the domi- ondary metabolites. This project will probe nant volatile sulfur compound emitted from three “cost/benefit” ideas that are often the ocean and may represent up to 90 percent woven into viable theories on the evolution of the sea-to-air biogenic sulfur flux. When of chemical defenses. these volatile sulfur molecules oxidize in the atmosphere, condensation nuclei can be • First, the Resource Availability Model of released which, scientists hypothesize, may chemical defense. The proposed research directly counteract the warming effects of will examine whether macroalgae grown anthropogenically produced CO2. Aquatic under carbon limitation (reduced light) systems – in particular the waters of the will produce quantitatively higher levels south polar regions – thus play a crucial role of defensive compounds than will those in one of the planet’s basic transactions. Yet grown in an optimal light environment; both the sources and the sinks of DMS and also whether antarctic macroalgae found in associated sulfonium compounds have yet the nutrient-rich peninsula region are likely to be fully identified and understood. to develop chemical defenses that include This research will examine the biogeo- nitrogen compounds. chemistry of water column and sedimentary • Second, the Optimal Defense Theory in DMS/DMSP (dimethylsulfoniopropionate), macroalgae and invertebrates. The pro- and the role of associated compounds (e.g., posed research will determine the extent dimethylsulfoxide, dimethylated polysul- to which chemical defenses are more fides) in Lake Bonney. A relatively simple abundant in tissues with a high energy aquatic system, Lake Bonney provides a content, such as reproductive tissue and highly tractable environment for investigat- offspring (larvae); also whether larvae ing the microbially mediated cycling of bio- relying on lecithin for nutrition have a genic sulfur because there is no turbulence, higher incidence of chemical defense than no grazers and little atmospheric exchange. do larvae relying on plankton. Preliminary data suggest that maximum lev- • Finally, using previous work in the Ross Sea els of DMS precursors may be found in the as a starting point, the investigation will deep-chlorophyll layer of the lake, a zone dom- map how chemical defenses may vary across inated by cryptophyte algae. In addition, DMS different areas; if they do vary, we will seek concentrations deep in the lake, where there is out possible underlying evolutionary factors. very little light (i.e., in the aphotic waters), are 16

BIOLOGY AND MEDICINE AND BIOLOGY among the highest recorded in a natural ular, Adélie penguins have been studied as aquatic system. These observations indicate an indicator of such anthropogenic impacts that precursors produced by trophogenic zone on antarctic resources as fishery catches and phytoplankton sink to the aphotic waters and disturbances created by tourism. sediments, where microbes decompose them Our 5 years of research include intensive to DMS and other sulfur compounds. The field study of three Ross Island penguin proposed research will define the sources colonies. We quantify reproductive effort and and sinks of DMS and associated compounds, success, food availability (access to food), diet and establish how they function in the overall quality, habitat use, and immigration/emigra- ecosystem. We hope to develop a model tion relative to colony size and environmental describing the biogeochemical transformations conditions (i.e., pack-ice cover). We employ of organo-sulfur compounds in Lake Bonney. several well-established techniques that have (BO-025-O) been successfully (but infrequently) used in antarctic biological research: Factors regulating population size and colony distribution of Adélie • Aerial photography: to evaluate the penguins in the Ross Sea. availability of nesting habitat, • Microwave images of sea-ice concentration: David G. Ainley, H.T. Harvey and Associates, to assess availability of feeding habitat, California. • Analysis of stable isotopes: to evaluate food quality, Over the past few decades, the Adélie pen- • Radio telemetry: to assess overlap in guin (Pygoscelis adeliae) colonies in the colony feeding areas, and Ross Sea region have grown dramatically in • Automatic systems: to log aspects of size. What demographic mechanisms might reproductive effort. account for this change? This collaborative project will investigate (in particular) the Landcare Research New Zealand (LCRNZ) possible effects of documented changes in has conducted two preliminary field seasons, the region’s climate. We will look at the nest- including the testing of new equipment. ing habitat as a function of access to food, This project will build on their results, and and hope to distinguish the relative impor- they will collaborate with us throughout the tance of the key resources that constrain the lifetime of the project. The LCRNZ work is growth of colonies. A number of behavioral independently funded. Researchers from and demographic mechanisms may influence the University of California-Santa Cruz, the a colony’s growth, relative to its initial size University of Wisconsin, and Beigel Tech- and distribution pattern – for example, a nology, will collaborate with those from H.T. phenomenon known as philopatry: The inter- Harvey and Associates and LCRNZ to accom- relationship between the balance achieved plish the project’s goals. by immigration/emigration and consequent (BO-031-O) breeding effort and success. As the first empirical study to consider the geographic structuring of a seabird population, Penguin/krill/ice interactions: The we expect our results to increase understand- impact of environmental variability ing of how populations regulate themselves, on penguin demography. and the patterns they follow when they dis- Wayne Trivelpiece, Montana State University. perse. We also hope to elucidate the effects of climate change, mediated through changes As the environment fluctuates, there are in sea-ice cover, on penguin populations. The direct effects on the structure and function results should also provide a context in which of antarctic marine ecosystems. Three exam- to interpret conflicting data on penguin popu- ples are the Adélie, gentoo, and chinstrap lation trends from existing programs; in partic- penguins of the antarctic, whose changing 17

numbers have been related to long-term microbes are implicated in the cycle and fate MEDICINE AND BIOLOGY changes in environmental conditions, in of a large suite of chemical elements. particular the possible effects of sea-ice The proposed research will examine the coverage on the availability of prey (krill). role of microbial influences on metal cycling We will explore the demographics of in four stratified lakes in the McMurdo Dry colonies of those three species living in Valleys: Lakes Fryxell, Hoare, Joyce and Miers. Admiralty Bay, King George Island, to test These lakes are characterized by unusually five hypotheses: stable redox transition zones, and are also especially amenable to a finely spaced sam- • The structure of the krill population is pling regime. Collectively, they represent a strongly affected by the extent of pack- broad range of water chemistries. ice, and its consequent impact on female The proposed research will test two fecundity and the survival of larvae. hypotheses: • Recruitment of penguins to their respective populations is affected by the extent of • In stratified water columns there should pack-ice cover during the winter prior to be a clear spatial difference between the the breeding season. onset of manganese reduction and the • The survival of penguin fledglings is corre- onset of iron reduction. Heavy metals and lated to the extent of pack ice cover during rare-earth elements will be seen to under- the winter following the breeding season. go co-cycling with manganese (Ma) rather • Adélie penguins return to the pack-ice than with iron. habitat during their first two-week-long • In all four lakes, Ma reduction will be asso- foraging trips following clutch competition ciated with the presence of carnobacteria to recover from prolonged fasting of the or other Ma-reducing organisms. courtship period. • Accessible pack ice in the early breeding Dissolved and particulate metal profiles will season has led to the evolution of discrete be examined at depths from the ice-water inter- population centers of Adélies from the face at the top all the way down to the sedi- Bellingshausen, Weddell, and Ross Sea ments. Profiles will be correlated with microbial populations. Ma-reduction assays, and with the presence of Ma reducers; these can be detected by screen- The Pygoscelis species of penguins are ing with Mn-oxide overlay agar plates and the major upper trophic level predators of nucleic acid hybridizations that function as krill (Euphausia superba) in the Antarctic probes for known manganese reducers. The Peninsula region. In trying to assess the research will include significant involvement potential impacts of fishery activities in this of undergraduates. area, it is imperative to first determine the (BO-041-O) distinct impact of a changing environment. (BO-040-O) Shell morphogenesis in giant agglutinated foraminifera. Microbial mediation of trace metal Samuel S. Bowser and Charles R. Hauer, cycling in four stratified antarctic lakes. Wadsworth Center, New York State William Green, Miami University at Oxford, Ohio. Department Health.

Aquatic environments often stratify; that A dominant member of the cold, deep-sea is, boundaries at different depths indicate sediments ecosystem is a group of giant pro- changes in the composition of the water. One tozoa, the agglutinated foraminifera, also of the basic processes in nature is reduction known as forams. For protection, these sin- by oxidation (redox), and redox boundaries gle-celled organisms encase themselves in can be found at specific water depths where architecturally elegant shells that they con- 18

BIOLOGY AND MEDICINE AND BIOLOGY struct by collecting, sorting, and cementing (within the permanent ice covers on the together sediment grains. The unique occur- lakes in the Taylor Valley) have been tenta- rence of these giant cells (greater than 1 mil- tively characterized in previous studies. limeter in size) in the shallow waters of This interdisciplinary research program will McMurdo Sound, Antarctica, allows for the use this background and context to explore study of the cellular and molecular aspects specific processes that allow for: of shell construction. In our project, we will use novel light- • the creation of liquid water (the essential microscopic methods to examine how agglu- element for life) in the permanent ice, tinated forams secrete and sculpt the adhe- • the survival and structuring of microbial sive matrix that binds sediment particulate in populations subjected to freezing and their shells. Comparative time-lapse photog- thawing, raphy of different foram species constructing • the production of substances that alter the shells will identify key steps in the processes physical attributes of the ice-crystal habi- that lead to the various shell morphologies. tat, and Peptide sequence analyses of the elastic • the nutrient supply to the microbial popu- proteins of the shells will provide valuable lations, which is essential for survival and insight into the chemical nature of foram whch largely determines net microbial bioadhesives. From a practical standpoint, growth and the accumulation of biomass. these cements may have important biotechnological and medical applications. Research on microbes in permanent ice We will also continue a study of the effects provides information on the ecology of of collection activities, as well as natural phys- microbes in ice ecosystems and promises ical disturbances, in this unique environment. to have biotechnological implications. The interdisciplinary research conducted for Furthermore, since water ice has been this project has implications for a number of detected within and beyond our own solar fields, including cellular development, evolu- system, these studies could provide insights tion, paleontology, marine products chemistry, into the conditions that might support extra- and ecosystem management. terrestrial life. (BO-043-O) (BO-044-O)

Microbial life within the extreme Influence of seasonal ice cover on environment posed by permanent pelagic and benthic communities: antarctic lake ice. Long time-series studies. Christian H. Fritsen, Edward E. Adams, James Kenneth L. Smith, Scripps Institution of A. Raymond, John C. Priscu, and Christopher Oceanography. P. McKay, Montana State University. The annual expansion and contraction of ice How does microbial life adapt to environ- cover in the Southern Ocean – the largest mental extremes, such as those found in seasonal process in the world ocean – causes Antarctica? One strategy is by association primary biomass production to fluctuate with sediment aggregates, sites where physi- extensively, and has a strong impact on both cal, chemical, and biological interactions pro- pelagic (open, upper sea) and benthic (deep- mote microbial growth under extreme condi- er, at the bottom) communities of fauna. This tions inherent to the ice environment. The 3- study at Port Foster, Deception Island, will to-20-meter-thick permanent ice covers on take advantage of a region that has seasonal the lakes of the McMurdo Dry Valleys, ice cover and which supports a pelagic and Antarctica, contain viable microbial cells in benthic fauna that are representative of the association with just such sediment aggre- antarctic coastal zone. gates. Specifically, certain ice aggregates 19

The study of the water column and ria; then characterization in the laboratory MEDICINE AND BIOLOGY seafloor will be structured as a long time- of their major physiological, biochemical, series, employing long-term, autonomous and genetic features; finally, in situ study of monitoring and sampling systems that were biogeochemical reactions carried out in natu- developed especially for use in Antarctica. ral populations of these organisms. We will deploy a bottom-moored, upward- Readily cultivable species of cold-adapted looking acoustic instrument on the seafloor photosynthetic bacteria will be isolated in for 12 months to monitor the vertical distri- pure culture. The isolation methods to be bution, abundance, and biomass of acousti- used are not the classical ones of liquid cally detectable macrozooplankton and enrichment but instead employ extincting micronekton in the water column. Collections dilution – this will ensure that rare as well will be made over this period using newly as abundant cultivable species are obtained. developed, vertically profiling pump sam- Variations in the enrichment approach will pling. Simultaneously, a time-lapse camera be used to isolate those cold-adapted species system will be moored on the seafloor to with particularly well developed and/or spe- monitor the spatial distribution, sizes, and cialized metabolisms. Examples are those movements of the epibenthic megafauna capable of autotrophic carbon dioxide fixa- component of the benthic community. tion, nitrogen fixation and the photocatabo- This deployment of instruments will allow lism of aromatic compounds. Field research us to focus on the effect of the seasonal will include isolation of new cultures from sea-ice cycle on the distribution, abundance, stratified antarctic lakes in the McMurdo Dry and biomass of the macrozooplankton and Valleys. A series of enrichment cultures estab- micronekton in the water column. Similar lished at different temperatures and growth questions about the deeper-dwelling epiben- rate measurements will yield isolates that thic megafauna will focus on distribution, possess the ability to grow over a range of size, abundance, and movements. Results temperatures. The Isolates will be phylogenet- from this study should provide a valuable ically characterized by 16s rRNA sequencing. foundation database to evaluate the pelagic This will permit us to determine which species and benthic community responses to season- are merely psychrotrophic (cold-tolerant) and al variability in the Southern Ocean. which are actually psychrophilic (cold-loving). (BO-050-O) The results of the research should fortify the knowledge of photosynthetic diversity. Biodiversity and biogeochemistry We anticipate identifying novel organisms for of antarctic photosynthetic bacteria. agricultural and biotechnological use, and Michael T. Madigan and Laurie A. Achenbach; for the study of photosynthesis and related Southern Illinois University, Carbondale. processes at low temperatures. Finally, we expect to broaden the diversity of known Environments classified as “cold” (average psychrophilic and psychrotrophic prokaryotes, temperature 5˚C or lower) comprise more and thus provide more data for the study of than 90% of the earth’s biosphere, yet rela- exobiology (the study of life beyond the planet). tively little is known about about the diversity (BO-195-O) and ecological activities of cold-adapted microorganisms – photosynthetic microorgan- Diving biology of emperor penguins. isms, in particular. This research will explore Paul J. Ponganis, Scripps Institution of the biodiversity of cold-adapted anoxygenic Oceanography. photosynthetic bacteria that are found in permanently cold antarctic habitats. The research Because the emperor penguin (Aptenoidytes takes a phased approach to biodiversity: forsteri) lives within the pack ice zone of Beginning with the enrichment and isolation Antarctica, its advanced ability to dive has of cultures of antarctic photosynthetic bacte- been the subject of interest for many years. 20

BIOLOGY AND MEDICINE AND BIOLOGY Emperor penguins routinely hunt for food for tion, permitting more of it to reach the Earth’s between 2 and 10 minutes, at depths ranging surface. Although research on the impact of from 50 to 500 meters. These birds have increased UV radiation due to ozone depletion reached a measured depth of nearly 550 has focused primarily on phytoplankton, a meters. The longest dives are not the deepest, smaller effort is being directed to the impacts however; the recorded longest of twenty-two on other food sources. minutes was nowhere near that record depth. During this collaborative project, we will This project will examine the diving physi- explore the effects of UV radiation upon bac- ology and behavior of emperor penguins in terioplankton. This involves the interactions the Ross Sea region of Antarctica. We hope between bacterioplankton and photochemi- to elucidate both the physiological and cal processes, as well as interactions with behavioral mechanisms underlying the higher trophic groups such as phytoplankton breath-holding capacity of these diving birds; and zooplankton. Several specific parameters also to understand how these physiological will be explored: limits may affect the natural diving behavior and ecology of the penguins; and further, • whether bacterial phytoplankton-coupling to use the unique adaptation of diving birds modifies bacterial response to UV radiation, to explore how organs and tissue tolerate • how seasonal changes in UV radiation oxygen deprivation. affect bacterial community dynamics, and The emperor penguin provides an excellent • how chemical photoproducts affect bacter- model to investigate the physiology and ial production. behavior of diving birds and mammals; in this case, thermoregulation, underwater behavior We hope to elucidate the molecular deter- and the homoeostatic regulation of myoglo- minants of changes in productivity, and also bin. We will focus on the role of decreased the molecular and physiological responses to body temperature in extending the duration changing UV radiation. The ultimate benefit of aerobic metabolism during diving. The would be a greater understanding of the presence of a small camera will permit us potential impact that changes in UV radiation to examine their behavior during their dives, can have on marine microbial communities. and to correlate changes in core and muscle (BO-200-O) temperature with which prey they ingest as well as with their wing stroke frequency. At The role of oceanographic features the molecular biology level, we will use the and prey distribution on foraging high myoglobin concentration in emperors and the large increases in myoglobin concen- energetics and reproductive success. tration during chick development to examine Daniel Costa, University of California at transcriptional control of the myoglobin gene. Santa Cruz. (BO-197-O) The Southern Ocean enjoys a high seasonal Ultraviolet-radiation-induced DNA productivity, in both coastal and pelagic environments. But observations over the last sev- damage in bacterioplankton in the eral decades show that behind this general Southern Ocean. productivity lies much variation – during the Wade H. Jeffrey, University of West Florida. year, and from year to year. Thus the prey available to vertebrate predators can vary sig- Strong evidence now shows that ultraviolet nificantly over time, and from place to place. (UV) radiation is increasing periodically over Since the late 1980s, scientists have record- certain locations in Antarctica and the ed this spatial and temporal variability for the Southern Ocean – a result of ozone depletion. northern South Shetland Islands region of the When ozone concentrations are diluted, the Antarctic Peninsula. The antarctic fur seal stratosphere is able to adsorb less UV radia- [Arctocephalus gazella], a subpolar migratory 21

otariid with a short lactation period, is an late localized studies to a broad spatial scale. MEDICINE AND BIOLOGY increasingly dominant marine predator of the One way to extend the results of photobiol- South Shetlands region. Its life-history pat- ogy point-measurement to large spatial scales tern is characterized by foraging trips alter- is by applying PAR (photosynthetically active nating with short visits to provide for a single radiation) mapping techniques to the UV radi- offspring; this pattern allows scientists to ation data gained by satellites. The mapping measure both maternal investment and the algorithm developed to date uses specific distribution/abundance of prey, on the same satellite images of cloud and ozone distribu- temporal and spatial scales. tion to estimate UV and PAR irradiance levels This project will quantify the foraging over large areas of the Earth’s surface. This costs and maternal investment associated work is underway, thanks to prior research with different strategies observed in popula- support; the goal of the current project is to tions of South Shetland antarctic fur seals. improve performance of the UV and PAR map- Using state-of-the-art techniques, we will ping algorithm. Since a significant fraction of determine the costs and benefits of different overall biological productivity occurs in waters foraging patterns correlated to: Energy near the coast, we will focus special attention expenditure, food intake, dive depth, dive on improving the performance of the mapping duration, time of day, dive frequency, swim technique in those regions. speed, and foraging location. These meas- Simulations made with Monte Carlo radia- urements will coincide with small- and large- tive transfer models suggest that these coastal scale oceanographic surveys to be conduct- regions are subject to significantly greater ed by the National Oceanic and Atmospheric UV surface irradiance. The field study will Administration’s Antarctic Marine Living deploy a newly modified surface radiometer Resources program, which also contributes with spectral sensors; this device optimizes to the support of this project. retrieval of cloud optical depth and surface The research will provide scientists a clear- albedo. This superior system should signifi- er picture of the life of a free-ranging marine cantly enhance our ability to test the accuracy vertebrate predator. The data should reveal of PAR, the mapping algorithm. patterns linking the biological characteristics We will also investigate how the new of the prey (composition, distribution, and AVHRR-3A satellite sensor might be used to abundance) and the physical characteristics improve the algorithm. It appears that infor- of the foraging environment with foraging mation from this new sensor could be useful success, maternal investment, and reproduc- for obtaining more frequent and accurate tive success. surface albedo maps, information vital to (BO-267-O) the mapping algorithm. We expect the development of these new Surface UV irradiance and PAR approaches to interpreting satellite and surface variability over Antarctica measurements to provide information critical Paul J Ricchiazzi and Catherine Gautier, for interpreting the impact of ozone reduction University of California, Santa Barbara. on the biological communities in Antarctica. (BO-279-O) Since discovery of the antarctic ozone hole in the early 1980s, concerns have grown about Planktonic invertebrate larvae and whether the consequent increase in ultraviolet biogeography of Antarctica. (UV) radiation reaching the Earth’s surface has a Rudolf Scheltema, Woods Hole negative impact on the Southern Ocean ecosys- Oceanographic Institution. tem. While subsequent photobiology research has shown there are negative effects on photo- Because continental drift has isolated antarc- plankton, zooplankton and fish larvae from the tic ecosystems since the Early Oligocene increased UV radiation, it is difficult to extrapo- (about 40 million years ago), most inverte- 22

BIOLOGY AND MEDICINE AND BIOLOGY brate fauna commonly found there are native duces students to the diversity of biological only to that region. Despite this extensive organisms in antarctic regions, and allows isolation, however, some benthic groups con- them to study unique aspects of biology that sist of significant proportions of non-native permit life in such extreme environments. species – from 20 to more than 50 percent. Long-standing questions in evolution and To account for such species, scientists have ecology (such as cold adaptation and food proposed that intermittent reciprocal limitation) about the biology of antarctic exchange must occur between populations organisms are examined through physiologi- resident on South America and Antarctica. cal experiments with organisms, studies of One hypothesis is that geographical distri- isolated cells and tissues, experiments on bution could be maintained and genetic protein structure and function, and molecular exchange accomplished through the passive analysis of genetics systems. Lectures dispersal of planktonic larvae. This project is emphasize physiological, biochemical, and targeted at this hypothesis; our objective is molecular biological approaches to under- to show that this dispersal actually occurs. standing the ecology and biological adapta- We must demonstrate two facts: tions of antarctic organisms. Student research projects follow these • larvae of sublittoral species actually can interwoven themes. The students should be found across the Drake Passage; fur- gain a rigorous understanding of the power – ther, that these do belong to species that as well as the limitations – of physiological, can be found in south american and biochemical, and molecular biological meth- antarctic faunas, and ods that are currently being used to answer • a hydrographic mechanism exists that can research questions in environmental science explain how passive transport of larvae and the biology of adaptation. occurs between the two continents. The course will be held in the Crary Science and Engineering Center at McMurdo To address these two requirements we will Station, Antarctica. This modern research make transects of plankton samples across facility provides state-of-the-art laboratory the Drake Passage and examine the possibil- facilities a short distance from the marine ity of cross-frontal exchange of larvae at the and freshwater environments where biologi- subantarctic and polar fronts of the Antarctic cal observations are made and material is Circumpolar Current; we will also explore the collected. The course will be taught in four possible transport of larvae in mesoscale modules: rings. Our results should demonstrate that other species may be profitably examined • Biological diversity of antarctic organisms: using molecular techniques that compare Evolution and molecular phylogeny; individuals from bottom populations of • Ultraviolet radiation: Effects on antarctic South America and Antarctica. organisms; (BO-281-O) • Invertebrates: Physiology, energy metabolism, and development; and McMurdo Station biology course; • Fish: Biochemical adaptations. Integrative biology and adaptation of antarctic marine organisms. By attracting an extremely competitive group of young scientists, this course intro- Donal Manahan, University of Southern duces new researchers to Antarctica and California. teaches students the modern research methods currently being deployed to study mecha- This international, advanced-level, graduate nisms that are unique to biology in Antarctica. training course will be organized and taught (BO-301-O) in Antarctica for one month during the austral summer of 1999-2000. The course intro- 23

Bentho-pelagic coupling on the west of biogenic materials and radionuclides (into MEDICINE AND BIOLOGY Antarctic Peninsula shelf: The impact midwater particle traps) with seabed deposi- and fate of bloom material at the tion and burial rates; this data should permit us to establish water-column and seabed preser- seafloor. vation efficiencies for these materials. Craig R. Smith, University of Hawaii Manoa; A better understanding of the spring/ and David DeMaster, North Carolina State summer production pulse on the WAP shelf University. should enhance our understanding of the impact of such fluctuations on seafloor com- Primary production in antarctic coastal munities, as well as carbon cycling in waters is highly seasonal; each spring/sum- Antarctic coastal systems. mer, an intense pulse of biogenic particles is (BO-303-O and BO-313-O) delivered to the floor of the continental shelf. This seasonal pulse may have major ramifica- Control of denitrification in a tions for carbon cycling, benthic (seafloor) ecology and the nature of material buried permanently ice-covered antarctic on the west Antarctic Peninsula (WAP) shelf. lake: Potential for a regulation by This project brings several disciplines together bioactive metals. in an effort to evaluate the bloom material – Bess B Ward, Princeton University. its fate, accumulation on the seafloor, and impact on the benthic community. Denitrification driven by bacteria is the We will work along a transect of three process by which nitrogen is lost from stations crossing the antarctic shelf in the ecosystems, and thus its rate and regulation Palmer Long Term Ecological Research study may directly affect both primary biological area. During five cruises throughout the production and carbon cycling, over both 1999-2000 research season, we will test the short and long time scales. This research following hypotheses: investigates a natural experimental system to be found in permanently ice-covered Lake • A substantial proportion of spring/summer Bonney in the Taylor Valley of East Antarctica export production is deposited on the WAP to ask: What is the role of bioactive metals in shelf as phytodetritus or fecal pellets. regulating denitrification? • The deposited bloom production is a source Lake Bonney has two distinct lobes, but in of labile particulate organic carbon (POC) only one does denitrification occur. Previous for bottom-dwelling organisms (benthos) for study has ruled out most of the obvious bio- an extended period of time (i.e., months). logical and chemical variables – which usually • Large amounts of labile bloom POC are influence denitrification – that might account rapidly subducted into the sediment col- for the difference between the two lobes. umn by the deposit-feeding and caching Denitrifiying bacteria are present in both lobes activities of benthos. of the lake, where tests of both temperature • Macrobenthic detritivores undergo rapid and salinity reveal conditions they can thrive. increase in numbers and biomass following Thus a paradox presents itself: Despite appar- the spring/summer POC pulse. ently favorable conditions, what is inhibiting denitrification in one lobe and not the other? To test these hypotheses, we will evaluate Our study entails a combination of culture seabed deposition and POC lability, patterns of experiments and field work to examine this POC mixing into sediments, seasonal variations paradox: in macrofaunal and megafaunal abundance, biomass and reproductive condition, and rates • experimenting with the denitrifying iso- of POC and silica mineralization and accumula- lates to determine metal tolerances and tion in the seabed. We will contrast the fluxes requirements for growth, 24

BIOLOGY AND MEDICINE AND BIOLOGY • measuring metal concentrations and metal speciation in surface transects and depth profiles, and • probing how denitrifying bacteria respond to alterations in the availability of certain metals.

By elucidating the relationship between microbial activity and metal distributions in Lake Bonney, we hope to add to scientific knowledge about the cycling of elements in other aquatic systems. We also expect to develop insights useful for evaluating the proposed use of paleo-denitrification indicators for past climate-reconstructions. Finally this research may shed light on the potential significance of the global marine denitrification/nitrogen fixation ratio to atmospheric carbon dioxide levels. (BO-310-O) 25

PACK-ICE SEALS resources (i.e., phytoplankton and ice-algae ANTARCTICPACKSEALS ICE At least half of the seals in the world inhabit stocks, and prey species such as fish, the pack ice around Antarctica. Six of the cephalopods and euphausiids), and on known 31 species are here, including about their numbers, distribution and diet. This 80 percent of the world’s total pinniped (car- collaborative project involves four different nivorous, aquatic mammals, including the groups of researchers, each responsible for walrus and all seals) mass. As a group, these different aspects of the field program: seals are one of the the dominant predators in Southern Ocean ecosystems. Changes in • Seals: Surveys by air and ship; capture and population size, growth patterns, life histo- attach instruments to track behavior; collect ries, and behavior provide a rich source of diet samples to better understand their potential information, about not only seal/ food habits. (Bengtson, Boveng, and Laake) pinniped biology, but also the history of their • Sea ice and hydrography: Measure near- environment in time and space. The Antarctic surface temperature, salinity, and sea-floor Pack Ice Seals (APIS) program is designed to bathymetry; record sea-ice and iceberg dis- track the distribution of these creatures and tribution and properties; collect ice cores; provide a better understanding of their ecolo- make CTD measurements from the ship gy. In January and February 2000, a research and from ice floes. (Jacobs and Ackley) cruise (through the pack-ice zone of the east- • Fish and cephalopods: Assess species ern Ross and western Amundsen Seas) will composition, distribution, and relative enable scientists to survey and sample along abundance, using hydroacoustic tech- six transects perpendicular to the continental niques and net tows; compare these data shelf. Each of these transects will pass with distribution and abundance data for through five environmental sampling strata – fish prey – such as krill – and for fish pred- continental shelf zone, antarctic slope front, ators – such as seals. (Torres and Daly) pelagic zone, the ice-edge front, and the open • Euphausiids and other zooplankton: Sample water outside the pack ice. This plan will abundance and distribution of krill and encompass all potential ecological zones other zooplankton, using hydroacoustic except for the open water. techniques, net tows and direct observations by divers; sample the demographics of Antarctic pack ice seals (APIS): krill at various depths within the study area; measure chlorophyll concentrations to eval- Ecological interactions with prey uate the diet of krill. (Quetin and Ross) and the environment. John L. Bengtson, Jeffrey L. Laake, and Peter L. A primary goal of this interdisciplinary Boveng, National Oceanic and Atmospheric research is to test a central hypothesis: Administration, National Marine Fisheries Measurable physical and biological features Service; Stanley S. Jacobs, Lamont-Doherty Earth in the Southern Ocean create an area of high Observatory; Joseph J. Torres, University of South biological activity by upper trophic level preda- Florida; Kendra Daly, University of Tennessee; tors. We expect this physical/trophic approach Stephen Ackley, U.S. Army Cold Regions to investigating an ecological web to develop Research Laboratory; Langdon Quetin and Robin insight into the interplay between pack-ice Ross, University of California, Santa Barbara. seals and the biological/physical features of antarctic marine ecosystems, and also to aid During surveys along each transect we will scientists in predicting seal population fluctu- gather data on the seals’ environment (i.e., ations attributable to environmental change. bathymetry, hydrography, sea-ice dynamics (BE-198-A, BE-198-B, BE-198-C and BE-198-D) and characteristics), their trophic (nutritional) 26

ANTARCTICPACKSEALS ICE Antarctic pack ice seals (APIS): Antarctic pack ice seals: Immunogenetic Distribution and abundance along diversity of antarctic pack ice seals the Oates and George V Coast. Brent S. Stewart and Niles E, Lehman, John L. Bengtson, Jeffrey L. Laake, and Hubbs-Sea World Res Institute. Peter L. Boveng, National Oceanic and Atmospheric Administration, National Like any species, pack-ice seals display Marine Fisheries Service. genetic variability among individuals. This component of the APIS program examines The Oates and George V coasts offer one of the two sets of genetic loci: primary sea-ice habitats for seals during the austral summer. This component of the APIS • the major histocompatibility complex, program entails surveying the numbers and which is involved in immune system distribution of four seal species: Crabeater responses; and (Lobodon carcinophagus), leopard (Hydrurga • the microsatellite locus, which does not leptonyx), Weddell (Leptonychotes weddellii), code directly for a gene product. and Ross (Ommatophoca rossii) seals. As some seals will be in the water during This dual approach will enable the team to the line transect surveys, we will correct our assess how much immunologically-relevant estimates by attaching satellite-linked, time- genetic variation occurs against the back- depth recorders to crabeater seals and deriv- ground of overall genetic variation. This ing estimates from published values for the study complements others on the health other species. As part of the survey, we will status of Antarctic ice seals. also monitor sea-ice characteristics, such (BE-229-O) as ice type, floe size, and percentage of coverage. Our objective is to investigate Antarctic pack ice seals: Health, the relationships among seal abundance, disease and pathology. bathymetry, and sea-ice characteristics. We Pamela K. Yochem and Brent S. Stewart, hope to produce new insights into the ecology Hubbs-Sea World Res Institute. of pack ice seals and to improve the precision of population estimates for these prominent There has been very little clinical data devel- (but still poorly-chronicled) members of the oped on the health of animals residing in upper-trophic antarctic marine ecosystem. undisturbed populations, seals in Antarctica (BE-198-E) in particular. Thus baseline information on the incidence of disease organisms and Antarctic pack ice seals: Nutritional pathology is critical. This component of the physiology and body condition of seals. APIS program undertakes to evaluate the Michael A. Castellini, University of Alaska, health, pathology, and exposure to disease Fairbanks. of antarctic pack ice seals encountered during the cruise. These data should enable us This component of the APIS program examines to investigate population dynamics as a seal nutritional physiology – health, body con- function of disease and pathology. dition and nutritional status – using a suite of (BE-230-O) biomarkers and morphometric indices. We will make comparisons within and between species, measuring: Blood and clinical markers, nutrition indices, lipid signatures and stable isotope signatures, as well an array of protein markers. This work complements other studies on the health status of Antarctic ice seals. (BE-199-O) 27

An examination of genetic patterns and ANTARCTICPACKSEALS ICE phylogeny of Antarctic pack ice seals: A coordinated multinational project. Donald B Siniff , Curtis Strobeck, and Ian Stirling, University of Minnesota-Twin Cities

Antarctica represents an enormous tableau against which to examine genetic diversity, especially for the discrete species of seals. This component of the APIS program is investigating genetic relationships within and between all four species. Since the seal populations tend to be widely dispersed, studies of genetic diversity may indicate patterns of evolutionary strategies, as well as common and divergent traits. We will employ microsatellite techniques to explore heterozygosity patterns within each species and to relate these patterns to what we know about their life histories. Mitochondrial DNA analysis should indicate the sequence of divergence among and between the four species, work that will be abetted through a collaboration with the University of Alberta, Canada. (BE-309-O) 28

LONG-TERM ECOLOGICAL RESEARCH ECOLOGICAL LONG-TERM LONG-TERM ECOLOGICAL cold desert region of Antarctica. The area is RESEARCH one of the most fascinating – and contrarian Ecology has taken its place among science’s – spots on Earth. In fact, it is as unearthly as vital, strategic disciplines, thanks to ever- any; NASA scientists wondering what condi- greater awareness of how the web of life and tions on Mars might be like came here – an Earth’s other dynamic processes constitute island of rock in a sea of ice, the largest ice- a coherent system. As part of this evolution, free area in Antarctica – where winds howl, NSF’s Long-Term Ecological Research Program what little water there is evaporates, and (LTER), begun in 1980, has grown into a net- where the only creatures that can survive are work of 21 research sites established to microorganisms, mosses, lichens, and rela- acquire long-term data sets from Alaska to tively few groups of invertebrates; higher Puerto Rico to Antarctica. Such a geographical forms of life are virtually non-existent. Thus spread is necessary to collect information on LTER projects based here take advantage of a variety of ecosystem types; such as, grass- perhaps the coldest and driest ecosystem on land, desert, forest, tundra, lake, stream, river, Earth, where life approaches its environmen- agricultural and coastal systems. To enhance tal limits; as such this may be seen as an understanding of ecological phenomena, “end-member” in the spectrum of environ- the program focuses on the role of cyclical/ ments included in the LTER Network. episodic events (ranging from years to decades to centuries) in the structure and Why is it necessary to conduct long-term function of these distinctive ecosystems. ecological research in such a place? All The Antarctic Biology and Medicine ecosystems are dependent upon liquid Program supports two of these LTER project water, and are shaped to varying degrees by sites – to facilitate research on unique aspects climate and material transport; but nowhere of antarctic ecology – one in the Palmer is this more apparent than in the McMurdo Station area of the Antarctic Peninsula and Dry Valleys. In very few of Earth’s environ- the other in the McMurdo Dry Valleys. ments do minor changes in solar radiation and temperature so dramatically affect the The Palmer Station/Antarctic Peninsula capabilities of organisms to grow and repro- LTER program is ideally sited to probe a duce as happens in the dry valleys. Thus, this fundamental issue: As the pack ice varies site may well be an important natural region- (seasonally and year-to-year), what happens al-scale laboratory for studying the biological to the antarctic marine community; that is, effects of climate changes attributable to how do ecological processes influence organ- human activity. While the antarctic ice sheets isms at different trophic levels? The Palmer respond to climate change on the order of Station LTER research program was initiated thousands of years, the glaciers, streams and during the 1991-1992 season with the installa- ice-covered lakes in the McMurdo Dry Valleys tion of an automatic meteorological station, often respond almost immediately. Thus, it is annual research cruises in the austral sum- there that the first effects of climate change mer, and a focused research program at the in Antarctica should be observed. station facility. During the austral fall and The overall objectives of the McMurdo Dry spring seasons, process study research cruis- Valleys LTER are to understand the influence es develop data that can be compared to of physical and biological constraints on the that collected from other coastal systems in structure and function of dry valley ecosys- the Antarctic Peninsula. tems, and to understand the modifying effects of material transport on these ecosystems. The McMurdo Dry Valleys LTER project is Though driven by the same basic processes more wide-ranging – also due to its unique found in all ecosystems – such as microbial site – and stages interdisciplinary study utilization and re-mineralization of nutrients – of aquatic and terrestrial ecosystems in a these dry valley ecosystems lack many con- 29

founding variables (biota levels of plants • chemistry of streams, lakes, and glaciers; RESEARCH ECOLOGICAL LONG-TERM and higher animals) present in other eco- W. Berry Lyons, University of Alabama system research. • flow, sediment transport, and productivity of streams; Diane McKnight, University of McMurdo Dry Valleys: A cold desert Colorado ecosystem. • lake pelagic and benthic productivity and microbial food webs; John Priscu, Montana W. Berry Lyons, University of Alabama at State University at Bozeman Tuscaloosa. • soil productivity; Diana Wall, Colorado State University and Ross A. Virginia, The largest ice-free area in Antarctica can be Dartmouth College found in the McMurdo Dry Valleys, located on • paleoclimatology, paleoecology and mete- the western coast of McMurdo Sound. In 1993, orological data collection; Peter T. this region was selected as a study site for the Doran, University of Illinois at Chicago National Science Foundation’s Long-Term • ecological modeling; Daryl Moorhead, Ecological Research (LTER) program. Among University of Toledo the most extreme deserts in the world, the dry (BM-042-F, BM-042-L, BM-042-M, BM-042-P, valleys are the coldest and driest of all LTER BM-042-W, BM-042-V, BM-042-D and BM-118-O) sites. Consequently, the biological systems are limited to microbial populations, microinverte- brates, mosses, and lichens. Yet complex troph- Long-term ecological research on the ic interactions and biogeochemical nutrient antarctic marine ecosystem: An ice cycles develop in the lakes, streams, and soils dominated environment. of the Dry Valleys. In the austral summer, solar Raymond Smith, University of California at energy produces glacial meltwater which sup- Santa Barbara. plies vital water and nutrients that are a primary influence on the ecosystems. Such mate- The Palmer Long-Term Ecological Research rial transport and climatic influences shape all (LTER) project is focused on one major eco- ecosystems, but nowhere is this more apparent logical issue: than in the McMurdo Dry Valleys. To what extent is the annual advance and The overall objectives of the McMurdo Dry retreat of sea ice a major physical determi- Valleys LTER project are to understand the nant of spatial and temporal changes in influence of physical and biological constraints the structure and function of the antarctic on the structure and function of dry valley marine ecosystem? ecosystems. These objectives will be pursued Evidence shows that this dynamic variabili- through a program of systematic environmen- ty of sea ice has an important (perhaps deter- tal data collection, long-term experiments, and minant) impact on all levels of the food web, the development of explanatory models. from total annual primary production to The McMurdo Dry Valleys LTER project breeding success in top predators. For exam- focuses on the marine and terrestrial ecosys- ple, variability in sea ice may affect prey and tems in the dry valley landscape as contexts predators directly by controlling access to to study biological processes and to explore open water or preferred habitats; or indirect- material transport and migration. ly, as changes in the sea ice cover affect other During the 1999-2000 field season, the follow- species that serve as food. We hypothesize ing studies will be conducted in the McMurdo that sea ice is a major factor regulating for Dry Valleys as part of the LTER project: • the timing and magnitude of seasonal • glacier mass balance, melt, and energy primary production; balance; Andrew Fountain, Portland State • the dynamics of the microbial loop and University particle sedimentation; 30

LONG-TERM ECOLOGICAL RESEARCH ECOLOGICAL LONG-TERM • krill abundance, distribution, and recruit- • Douglas Martinson, Columbia University ment; and (BP-021-O); • survivorship and reproductive success of • Langdon Quetin, University of California top predators. at Santa Barbara (BP-028-O); • Raymond Smith, University of California These factors probably differ for different at Santa Barbara (BP-032-O); and key species, as the magnitude and timing of • David Karl, University of Hawaii (BP-046-O). sea-ice changes can have very specific local impacts. What remains unclear are the ramifications for the whole antarctic ecosystem. As one of the basic examples: Greater sea- ice areal coverage promotes more available antarctic krill (a primary food), which enhances the survivorship and reproductive success of Adélie penguins. Thus, the overall objectives of the Palmer LTER project are to:

• document not only the interannual variability of annual sea-ice and the corresponding physics, chemistry, optics, and primary production within the study area; but also the life-history parameters of secondary producers and top predators; • quantify the processes that cause variation in physical forcing and the subsequent biological response among the representative trophic levels; • construct models that link ecosystem processes to environmental variables and which simulate spatial/temporal ecosystem relationships; and then • employ such models to predict and validate ice-ecosystem dynamics.

A key challenge for the Palmer LTER project is to characterize and understand the many cross-linkages that have developed in the antarctic ecosystem: Environmental phenomena vary, over time and across areas, having both physical and biological consequences; these changes in turn can develop other loops and linkages that influence each other. The participants for the 1998–1999 field season will be:

• William Fraser, Montana State University (BP-013-O); • Maria Vernet, Scripps Institution of Oceanography (BP-016-O); 31

ENVIRONMENTAL MONITORING habitats – in and around McMurdo Station, ENVIRONMENTALMONITORING PROGRAM PROGRAM locating them precisely and tracking them Recognizing that scientific research and related over time. logistic support can have effects on the antarc- Using a combination of aerial photography tic environment, the Antarctic Treaty Consul- and point-data sampling grids at various spa- tative Parties adopted recommendations on tial scales, we will measure a series of attrib- environmental monitoring in Antarctica with utes indicative of change within these two two important goals: To detect any unforeseen habitats. Our objectives are to determine: effects and to verify the actual impact and scope of those effects that were anticipated. • the spatial and temporal scales of change The Protocol on Environmental Protection and its origin; to the Antarctic Treaty also requires that envi- • how efficient this observational system ronmental impacts be monitored. The U.S. is in documenting relevant changes in Antarctic Program (USAP) is developing an important habitat characteristics; and Environmental Monitoring Program designed • the usefulness of various approaches to detect and measure any impacts from sci- to reference or control locations. ence and operations at its research stations in Antarctica. Only with a sustained and We will use modern GIS techniques and coherent monitoring program can a reliable geostatistical methods to organize these basis for sound environmental management diverse datasets into a coherent, coordinated decisions – and possible improvements – be framework. The results should provide funda- established. Data obtained from the monitor- mental scientific information for developing a ing program will be used to document base- long-term strategy to document and minimize line conditions, verify operational impact, and the impacts of future science and support monitor activities undertaken to recover from operations on antarctic resources and values. accidental impacts to the environment. (EO-318-O)

Spatial and temporal scales of human disturbance—McMurdo Station, Antarctica. Mahlon Kennicutt, II, Texas A&M University.

Antarcica represents perhaps one of the most carefully-tended and strictly-monitored habitats on Earth. Aside from the obvious desire to pro- tect the flora, fauna and the atmosphere of a relatively pristine environment per se, there is the value the extreme southern latitudes provide as a virtual baseline barometer of global pollution. The Antarctic Treaty’s Protocol on Environmental Protection, supplemented by the policies and practices of the nations who work and do science there, have combined to focus scrutiny on any anthropogenic (exogenous) impacts that can be foreseen or detected. This three year project will establish a system of observations that should enable the United States to be more aware of any such impacts – on both marine and terrestrial 32

GEOLOGY AND GEOPHYSICSGEOLOGYAND GEOLOGY & GEOPHYSICS PROGRAM focused on by the Geology and Geophysics Antarctica is not only one of the world’s seven program include: continents, but also comprises most of one of its dozen major crustal plates, accounting for • determining the tectonic evolution of about nine percent of the Earth’s continental Antarctica and its relationship to the evolu- (lithospheric) crust. Very little of this land is tion of the continents from Precambrian visible however, covered as it is by the vast time (600 million years ago) to the present; East Antarctic Ice Sheet and the smaller West • determining Antarctica’s crustal structure; Antarctic Ice Sheet. The ice sheets average • determining how the dispersal of antarctic some 3 kilometers deep – a virtual vault, 90 continental fragments may have affected percent of the ice on Earth is here. And it is the paleocirculation of the world oceans, heavy, depressing the crust beneath it some the evolution of life, and the global climate 600 meters. These physical characteristics, (from prehistoric times to the present); while not static, are current. Yet thanks to the • reconstructing a more detailed history of sciences of geology and geophysics, powered the ice sheets, identifying geological con- by modern instruments and informed by the trols to ice sheet behavior, and defining paradigm of plate tectonics/continental drift, geological responses to the ice sheets on Antarctica is also a time machine. regional and global scales; and Geologists have found evidence that there • determining the evolution of sedimentary was once a forested supercontinent in the basins within the continent and along con- Southern Hemisphere, which they call tinental margins. Gondwanaland. Before the Earth’s constantly shifting plate movement began to break it up All of these problems will be simplified 150 million years ago, Antarctica was a core as scientists improve their models of where, piece of this assembly; its adjoining land when, and how crustal plate movement has since become Africa, Madagascar, India, wrought Antarctica and its surrounding Australia and South America. The Antarctic ocean basins. The program funds investiga- Plate drifted south at little more than a cen- tion into the relationships between the geo- timeter each year, but geologic time eventual- logical evolution of the antarctic plate and ly yields cataclysmic results: The journey the life and processes that can be deduced moved it into ever colder, high-latitude cli- to accompany it: Paleocirculation of the mates, at a rate of about 4°C for each million world ocean, paleoclimate of the Earth, and years; eventually life conditions had changed the evolution of high-latitude biota. A current dramatically, and Antarctica arrived at a near emphasis is the West Antarctic Ice Sheet polar position. This astounding history of rock Program (WAIS), research on the smaller of and life on Earth has left a stratigraphic and the continent’s two ice sheets, conducted fossil record, locked in and beneath the ice, also under the aegis of the Glaciology pro- the sea, and in the bedrock below both. gram. Several important research support As the ice sheets developed, they assumed activities are also underway: what has become a key role in modulating global climate, through their interaction with • Meteorites: In a partnership with NASA oceanic and atmospheric circulation. As a and the Smithsonian Institution, the bonus, the South Pole also presents a strate- program supports meteorite collection gic point to monitor the Earth’s current seis- through ANSMET, the Antarctic Search mic activity. Antarctica is the highest conti- for Meteorites, and chairs an interagency nent on Earth (about 2,150 m above sea committee, responsible for curating and level), with its fair share of mountains and distributing samples of the antarctic volcanoes; thus many generic questions of meteorites. interest to earth scientists worldwide also • Mapping and geodesy: In partnership with apply to this region. Some specific issues the U.S. Geological Survey, the program 33

supports mapping and geodetic activities as flow may have developed within the context of GEOPHYSICSGEOLOGYAND an investment for future research in earth Cenozoic rifting on the eastern Ross embayment sciences. The U.S. Antarctic Resources margin (on the one hand), or, rather, within the Center (US-ARC) constitutes the USAP volcanic province in Marie Byrd Land; or per- contribution to the Scientific Committee haps due to a combination of both. on Antarctic Research (SCAR) library system Faulting and volcanism, mountain uplift, for earth sciences information; housed here and glacier down-cutting appear to be active is the largest collection of antarctic aerial now in western Marie Byrd Land, where gen- photographs in the world, as well as many erally east-to-west-flowing outlet glaciers maps, satellite images, and a storehouse of incise much older (Paleozoic and Mesozoic) geodetic information. bedrock, and deglaciated summits indicate a • Marine sediment and geological drill cores: previous north-south glacial flow direction. In a partnership with the Antarctic Marine Our study relies on Support Office for Geology Research Facilty at Florida State Aerogeophysical Research (SOAR) to collect University, the program manages and dis- data; this facility uses a high-precision differ- seminates marine sediment and geological ential global positioning system to support drill cores mined in Antarctica. The collection a laser altimeter, ice-penetrating radar, a includes an array of sediment cores as well towed proton magnetometer, and a Bell as geological drill cores from the Dry Valley BGM-3 gravimeter. Drilling Project, the CIROS drilling program, SOAR should help us to glean glaciology and the Cape Roberts Drilling Project. The data useful for studying driving stresses, facility fills requests for samples from glacial flow, and mass balance in the WAIS. researchers worldwide, and also accommo- The ground program, centered on the south- dates visiting researchers working on site. ern Ford Ranges, will map: Glaciated surfaces and deposits; small-scale brittle structures, Air-ground study of tectonics at the to determine the regional kinematics; and boundary between the eastern Ross datable volcanic rocks to establish the embayment and western Marie Byrd geochronology. We will also determine the relative significance of fault and joint sets, Land, Antarctica: Basement geology the timing relationships between them, and and structure. how they were probably formed; as well as Christine S. Siddoway, Colorado College. exposure ages for erosion surfaces and moraines. To aid in the interpretation of The West Antarctice Ice Sheet (WAIS) is a potential field data and to aid paleomagnetic complex, dynamic system. In Neogene time studies, we will sample magnetic properties (between about 1.6 and 23.3 million years ago), and density as well as take ground-based movement and shifting of the Earth’s crustal gravity measurements and oriented samples. plates (tectonics) contributed to the formation By combining these airborne and ground of WAIS and associated ice streams of the investigations, we expect to gather the basic region. A better understanding of what may data to describe the geology and structure at the have happened will contribute to a comprehen- eastern boundary of the Ross embayment, in sive model for the Cenozoic origins of the Ross both outcrop and ice-covered areas. These data Sea Rift, and should also help specify the should help distinguish between Ross Sea Rift- extent of plume activity in Marie Byrd Land. related structural activity and tectonic uplift/fault- This project undertakes both geologic and ing that may have occurred on the perimeter of geophysical investigations of these two regions. the Marie Byrd Land dome and in the volcanic The goal is to determine the tectonic history of province. Ultimately, the aerogeophysical data the region during the Cenozoic Era (the last 65 and the outcrop geology should permit us to million years); specifically to learn whether infer the geology that resides beneath the WAIS. Neogene structures that localized outlet glacier (GF-088-O) 34

GEOLOGY AND GEOPHYSICSGEOLOGYAND Global positioning system measure- Barbara and a team at the Jet Propulsion ment of isostatic rebound and tectonic Laboratory at the California Institute of deformation in Marie Byrd Land, West Technology – Andrea Donnellan, Carol Raymond, and Erik Ivins – brings together Antarctica. experts in western Marie Byrd Land geology Bruce Luyendyk, University of California at and tectonics, tectonic geodesy, and lithos- Santa Barbara. pheric deformation. (GF-121-O) The Ross embayment and western Marie Byrd Land are part of the west antarctic rift Structure and sedimentology of the system. Most scientists agree that this region is undergoing active deformation, but the Beardmore Group, Antarctica: Latest rates and causes of deformation remain Neoproterozoic to Early Paleozoic essentially unknown. Tectonic extension may tectonic evolution of the east be occurring in the Ross embayment as West antarctic margin. and East Antarctica continue to separate. John W. Goodge, Southern Methodist University. Crustal uplift could be occurring in western Marie Byrd Land due to isostatic rebound The Neoproterozoic to early Paleozoic transi- following the last glacial age. tion (700 to 500 million years ago) marked a If tectonic extension is occurring in the critical period in the history of the Earth: A embayment – depending on its magnitude supercontinent known as Rodinia coalesced, – it could greatly influence global plate cir- then fragmented, and subsequently amalga- cuit calculations. It could also constrain our mated as a second supercontinent, known as understanding of the history of extension in Gondwanaland. During these events, major the embayment and the consequent uplift mountain-building, continental erosion, history of the Transantarctic Mountains. species diversification, sea-level fluctuations, Postglacial rebound in western Marie Byrd and changes in seawater composition took Land would depend on when and how the ice place. Scientists have built detailed records sheet was configured during the Last Glacial of sea-level fluctuations, faunal distributions, Maximum. The big question is whether the and post-depositional tectonism out of conti- ice sheet collapsed in mid-Holocene time. nental margin sedimentary sequences. This study will install three continuous and The Beardmore Group in Antarctica is one autonomous global positioning system (GPS) of these sequences, undoubtedly a significant stations on outcrops in western Marie Byrd element in the evolution of the east antarctic Land, on baselines of around 100 kilometers. craton (the main, relatively stable nucleus of These stations will gather data over a 4-year the continent). Yet very little is known about period and operate in concert with GPS sta- its depositional or tectonic history. tions being installed in the Transantarctic Previous workers have suggested that the Mountains in a separate project; the result entire Beardmore Group is Neoproterozoic in will be a baseline array all across the Ross origin, and that it records two distinct deforma- embayment. The array will also detect strain tions, the well-known Ross orogeny and an gradients in western Marie Byrd Land. earlier, cryptic, “Beardmore” orogeny. Field This system should determine crustal strain reconnaissance and geochronologic studies rates to an accuracy of 1 millimeter per year reveal portions of the Beardmore Group to be for horizontal, and 2 millimeters per year for significantly younger than previously believed, vertical. The strain data from western Marie which would support the view that Ross defor- Byrd Land and the Transantarctic Mountains mation was the exclusive formative event. should enable us to construct both tectonic These preliminary data reflect uncertainty in extension and glacial rebound models. the geologic relations of these rocks; we This joint project between Bruce Luyendyk believe the Neoproterozoic tectonic history of the University of California at Santa for the region must be revised. 35

To improve understanding of the to collect the ground-control data necessary GEOPHYSICSGEOLOGYAND Beardmore Group’s depositional history and to transform existing geodetic data to an its role in orogenic events shaping the outer earth-centered system suitable for future margin of Gondwanaland, we will conduct: satellite mapping programs. LandSat data will be collected as part of satel- • detailed field study of the stratigraphy, lite image mapping activities; this will permit sedimentology, and structure; continued publication of additional 1:50,000 • provenance (source) study of graywackes scale topographic maps in the McMurdo Dry to constrain the depositional setting of the Valleys region. Such topographic maps provide turbidites; a uniform base map on which to portray scien- • determination of carbonate isotopic com- tific information (from geology, glaciology, biolo- positions for comparison with the global gy and other studies) such that it is spatially carbon-isotopic refinement of depositional accurate. These, as well as the satellite image age(s) through uranium-lead dating of maps, are used by scientists to plan and exe- detrital and igneous zircons; and cute future research work. Spatially-referenced, • thermochronology to constrain the defor- digital cartographic data will be produced in mation ages with argon-isotopes. tandem with the published maps. (GO-052-M, GO-052-P and GO-052-S) During the 1999 – 2000 austral summer, we will continue to test a recently proposed model Response of the East Antarctic Ice Sheet for Beardmore Group deposition and deforma- to Middle Miocene global change. tion; namely that Ross activity caused the lat- David R Marchant, Boston University. est Neoproterozoic/Early Paleozoic(?) rift-margin sedimentation and structural inversion. As evidence of global climate change contin- These explorations should help to resolve ues to accumulate, scientists concentrate long-standing uncertainties in the geologic on models that might indicate what impacts history of Antarctica, and improve our under- such change could have. For example what standing of global paleogeographic and plate- could happen to the East Antarctic Ice Sheet? tectonic events during the formation of the One of the largest known global climate supercontinent at the close of the Proterozoic. shifts occurred in Middle Miocene time (GO-014-O) (between about 15.6 and 12.5 million years ago). As the isotopic composition of oxygen Antarctic mapping and geodesy. in the oceans shifted, dramatic global cooling Jerry L. Mullins and Richard E. Witmer, and reorganization of ocean circulation pat- U.S. Geological Survey. terns can be seen. This dramatic and irreversible shift set the stage for modern oceanic Geodetic surveying, aerial photography, and atmospheric circulation, and for the bipo- remote sensing (principally using several vari- lar ice ages that have dominated climate eties of satellite imagery), and mapping are records for the last 12.5 million years. How did all activities necessary for the successful oper- Antarctica respond to this great climate shift? ation of a multifaceted scientific and explo- Could growth of the antarctic ice sheet have ration effort in Antarctica. The U.S. Geological initiated this shift? If so, how might future fluc- Survey provides these support activities to tuations in the volume of ice on East Antarctica the U.S. Antarctic Research Program. influence atmospheric and oceanic circulation? Year-round data acquisition, cataloging, Recently there was an unexpected break- and data dissemination activities will contin- through in antarctic geology, discovery of ue in the U.S. Antarctic Resource Center for Miocene-age volcanic ashes interbedded geospatial information. Field surveys will be with surficial sediments in southern Victoria conducted in support of specific research Land. These terrestrial deposits provide projects, and as part of a continuing program unambiguous data from which to generate 36

GEOLOGY AND GEOPHYSICSGEOLOGYAND precise climatic and glaciological reconstruc- Present day volcanism exemplifies this over- tions of how the global climate changed and all process of differentiation – so many differ- the ice sheet evolved. This site appears to be ent varieties of lava erupt – yet scientists have the only place in Antarctica where pristine, not been able to relate this diversity to the Miocene-age, unconsolidated deposits are prolonged and detailed deep-Earth processes preserved at the ground surface. These data that undoubtedly generate it. Solidified bod- are further permitting scientists to address ies of magma (plutons) that were once deeply key questions, such as: buried and are now exposed through erosion also furnish evidence, but most often how • What contributing factors in Antarctica these plutons relate to the magmatic-volcanic led to the abrupt global cooling about system is not clear. 14 million years ago? This research is pointed at this fundamental • Does the middle Miocene shift in the problem: We will examine magma crystallization isotopic composition of the oceans signify processes by studies of sills from the Ferrar a major expansion of east antarctic ice? Group in Antarctica. These studies should • Or rather, does this isotopic shift instead expose the relationship of plutonism to volcan- reflect a change in ocean temperature or ism and may provide some important insights circulation? on planetary magmatism. The Ferrar magmatic • And a related question – When did cold, hyper- system of the McMurdo Dry Valleys, Antarctica arid, polar-desert conditions (signifying the (Ferrar-DV) exemplifies the emerging global par- development of the polar East Antarctic Ice adigm. Magmatic sheets or sills occur in stacks, Sheet) first evolve in Antarctica? connected below to a deep-seated magmatic source and above to a volcanic center. In analyzing these deposits, we expect to The world’s major magmatic systems reveal obtain precise chronological control, based this pattern, as they tend to occur at ocean on 50 laser-fusion isotopic analyses of in-situ ridges (e.g., Kilauea, Mt. Etna, Stillwater, and volcanic ashes and 20 cosmogenic, exposure- Rum, among many others). Only the Ferrar- age analyses of ancient deposits. We also expect DV, however, clearly reveals the critical physi- to develop a coeval record of the Miocene paleo- cal and chemical connections between the climate, based on textural changes in alpine deep, mush-dominated system and the near- drifts, the areal distribution of ice-marginal lakes, surface, pre-eruptive sill system. the abundance of dated, patterned ground and This project seeks to ascertain the full ventifact pavements, and the geochemistry of physical and chemical nature of the Ferrar-DV buried soils and volcanic-ash deposits. magmatic system, by: (GO-054-O) • fully delineating its vertical and horizontal The ferrar magmatic mush column extent and explaining how it was estab- system, Dry Valleys, Antarctica. lished; Bruce D. Marsh, Johns Hopkins University. • explaining the mechanics of formation of the Dais layered intrusion; Earth’s basic structure was formed by • producing a map of Ferrar rocks through- processes involving the crystallization of out the Dry Valleys; and magma (molten rock). Operating on billion- • producing a 3-D model of the opx tongue year time scales, these processes have pro- and feeder system. duced a wide diversity of rock types. In turn, The central science goal is to elucidate a these different elements comprise the conti- rarely seen transition between plutonic and nents and the ocean basins – the basic volcanic systems, one which may have impli- surface features of Earth. Yet many of the cations fundamental to planetary magmatism. details of these physical and chemical (GO-056-O) processes remain obscure. 37

Antarctic search for meteorites. Other targets this season are the Goodwin GEOPHYSICSGEOLOGYAND Ralph Harvey, Case Western Reserve University. Nunataks icefields (near Foggy Bottom) and the MacAlpine Hills icefield. Another signifi- Since 1976, ANSMET (the Antarctic Search cant effort will involve reconnaissance of ice- for Meteorites program) has recovered more fields further north, in the Miller and Geologist than 9,000 meteorite specimens from loca- ranges surrounding the headwaters of the tions along the Transantarctic Mountains. Nimrod Glacier. Antarctica is the world’s premier meteorite After the main party returns to McMurdo in hunting ground for two reasons: early January, a two-person ANSMET field party will visit the Elephant Moraine icefield north- • Although meteorites fall all over the globe west of the Allan Hills. In addition to trying to at random, the likelihood of finding a mete- re-establish several key survey points to speci- orite is enhanced if the background material fy meteorite find locations across the region, is plain and the accumulation rate of terres- ANSMET personnel will participate in a robotics trial sediment is low; this makes the East experiment in meteorite collection. The Antarctic Ice Sheet the perfect medium. National Aeronautics and Space Administration • Along the margins of the sheet, ice flow is and investigator Dimi Apostolopoulos will sometimes blocked by mountains, stage a number of experiments here that could nunataks, and other obstructions; this yield data useful for future collection efforts exposes slow-moving or stagnant ice to elsewhere in the solar system. the fierce katabatic winds which can dimin- (GO-058-O and GO-059-O) ish the ice and expose what is known as a “lag deposit” of meteorites (a representa- A test for Tertiary-age deep fluvial tive portion of those that were sprinkled incision and strongly melting valley- throughout the volume of ice lost to the glaciers in the McMurdo Dry Valleys wind). When such a process continues for using ground-penetrating radar: millenia, the concentration of meteorites unveiled can be spectacular. A pilot project. Michael Prentice, University of New Hampshire. It is important to continue recovering antarctic meteorites because they are the The study of geology, as with most sciences, only currently available source of new, non- is closely linked to technological advance- microscopic extraterrestrial material. As ments in measurement and exploration. This such, they provide essential “ground truth” research deploys ground-penetrating radar (existence proof) about the composition of (GPR) – a technique not previously used on asteroids, planets, and other bodies of our antarctic sediments – to study two types of solar system. This connection brings The large morphologic features in the McMurdo National Aeronautics and Space Dry Valleys in order to address controversy in Administration (NASA) into ANSMET as a col- the geology of Antarctica. laborator; their robotics development project will aid the search in the Allen Hills region • First, spurlike aprons. Situated below tribu- During the 1999-2000 field season, ANSMET tary valleys that project into trunk valleys, will visit the Walcott Névé region (just north spurlike aprons have been interpreted to be of the headwaters of the Beardmore Glacier, remnants of bedrock fluvial spurs; as such, and just south of the Law Glacier). This they provide a record of preglacial fluvial has been a prolific source of meteorites for incision of trunk-valley floors to sea level. If ANSMET field parties. Our primary target will this interpretation is correct, it follows that be an area informally called “Foggy Bottom” a major sector of the Transantarctic at the south end of the Walcott Névé, where Mountains landscape is largely fluvial and 5 previous seasons of work have recovered not glacial in origin. A corollary to this thesis over 3,400 meteorites. requires the antarctic ice/climate system 38

GEOLOGY AND GEOPHYSICSGEOLOGYAND to have been quite stable throughout the Late Cretaceous and Cenozoic Tertiary ice ages, that is, restricted to its reconstructions of the southwest current high-polar state. Pacific. Steven C Cande, Scripps Institution of We believe the bedrock/spur interpretation Oceanography. to be unsupported and – considering form and structure analyses – unlikely. We will Crustal plate motion is never as predictable as conduct a GPR survey of the best example earth scientists would like – witness the devas- (below Denton Glacier in eastern Wright tation wrought by unpredicted earthquakes. In Valley) in search of relevant data. Antarctica, there is controversy regarding a possible missing plate boundary, as well as tecton- • Second, large moraines. Using form and ic uncertainties in the motion between East and structure analyses, we postulate that large West Antarctica; in particular, questions about moraines are stratified. If so, these fea- the relative drift between major hotspot tures reflect deposition from valley glaciers groups. The plates of the Southwest Pacific that possessed strong melting margins. region are rotational, so that earthquakes are Deposition of this type implies that at least relatively rare. Still, the models that describe the regional antarctic ice/climate system the motion of the Pacific, Antarctic, and was in a subpolar state – that is, was Australian plates – and the continental frag- warmer, wetter, and more dynamic than ments of New Zealand, West Antarctica, Iselin the high-polar state. Bank, East Antarctica, and Australia – could be improved. This is the object of this research. We will use GPR to study three moraines Previous work has documented mid-Tertiary whose internal composition is unknown, and seafloor spreading in a NNW-striking direction, which might provide evidence on the issue. producing magnetic anomalies between East Two such moraines are in central McKelvey and West Antarctica. This would explain the Valley, possibly associated with glaciolacustrine approximate 150 km-opening of the Adare sediment; the other is in central Wright Valley, Trough, north of the Ross Sea. The hypothe- and associated with glaciomarine sediment. sized motion, however, is insufficient to resolve In addition, we will examine a few distinctive the apparent discrepancy between the actual drift patches that crop out asymmetrically on plate motions and those that would follow from trunk-valley walls, using conventional surficial the assumption that the hotspots were fixed. geologic techniques. These patches appear to The motion between East and West be traceable into high alpine valleys and thus Antarctica indicates a very small rotation. may have been deposited from expanded Thus, scientists would like to develop mod- alpine glaciers that merged with trunk-valley els of finite plate rotation in this area to a glaciers. If true, these patches record the syn- high degree of accuracy, particularly for older chronous advance of alpine and trunk-valley times. This goal is now attainable, based on glaciers, which would imply that the coeval the analysis and interpretation of data that climate was significantly wetter and warmer should result from this project, in conjunc- than it would have been in the high-polar state. tion with other data sets compiled by (GO-063-O) Japanese and Italian scientists on recent cruises in the region. Our new marine geophysical data will be collected on selected transits of the Nathaniel B. Palmer. We hope to: 39

• improve the rotation model for mid-Tertiary taphonomic/depositional settings for each GEOPHYSICSGEOLOGYAND extension between East and West of these localities. Antarctica by directly considering the plate During the project’s second year, we will boundary between the Pacific and prepare and study the vertebrate finds, Australia plates in the calculation of including investigations of the evolutionary Australia-West Antarctica motion; significance of the member taxa of these • improve the reconstructions for Late high latitude Mesozoic faunas. Cretaceous and Early Tertiary times by (GO-074-O) including new constraints on several boundaries not previously used in the Dry valleys seismograph project. reconstructions; Kent Anderson, U.S. Geological Survey. • address the issue of the fixed position of global hotspots through the implications One recurrent issue in seismography is of new rotation models; and, “noise” – that is background phenomena • re-examine the geophysical data from the that can interfere with clear and precise western Ross Sea embayment in light of a readings. The Dry Valleys Seismograph model for substantial mid-Cenozoic extension. Project – a cooperative undertaking with (GO-071-O) the New Zealand Antarctic Program – was established to record broadband, high- Vertebrate paleontology of the Triassic dynamic-range, digital seismic data from to Jurassic sedimentary sequences the remote Wright Valley, a site removed in southern Victoria Land and the from the environmental and anthropogenic Beardmore Glacier area, Antarctica. noise ubiquitous on Ross Island. The Wright Valley site provides one of the William R Hammer, Augustana College. few locations on the continent with direct access to bedrock. The station there consists Vertebrates of several different ages span- of a triaxial broadband borehole seismome- ning the Triassic to Jurassic (roughly from ter [100 meters (m) deep] and a vertical short- 250 to 150 million years ago) have been period instrument at 30 m. The seismological discovered in recent years in Antarctica. data are digitized at the remote location, These fossils provide paleontologists a telemetered by repeaters on Mount Newell unique opportunity to study the evolution and Crater Hill, and received eventually by of high latitude faunas, which in turn the recording computer at the Hatherton contribute to our understanding of high Laboratory at Scott Base, where a backup latitude climates during the Mesozoic. archive is created. This project undertakes antarctic field These data will eventually reach the inter- work in the Transantarctic Mountains, to national seismological community; from search for and collect new terrestrial verte- Hatheton they pass via a point-to-point proto- brates of Triassic and Jurassic age. During col link to the Internet at McMurdo Station the austral summer of 1999-2000, with the and thence to the Albuquerque Seismological support of helicopters operating from Laboratory for general distribution. This data McMurdo Station, we plan to explore expo- set has beautifully complemented the data sures of the Feather and Lashly Formations from other seismic stations operated by the in southern Victoria Land. These field efforts Albuquerque Seismological Laboratory at will concentrate on finding exposures equiva- Amundsen-Scott South Pole Station, Palmer lent to the Hanson Formation – where the Station, and Casey, the Australian station. only Jurassic dinosaur fauna from Antarctica GO-078-A was found – as well as searching for new Middle to Upper Triassic fossil vertebrates. We will also construct interpretations of the 40

GEOLOGY AND GEOPHYSICSGEOLOGYAND Mount Erebus volcano observatory: • deploy a temporary network of broadband Gas emissions and seismic studies. stations to augment the results of a previ- Philip R. Kyle and Richard C. Aster, New ous pilot study; and Mexico Institute of Mining & Technology. • expand development of current software to allow automatic and precise timing of Mount Erebus on Ross Island is Antarctica’s earthquake occurrences and thus allow most active volcano; also the only one with a precise locations to be determined. persistent convecting lake of molten silica and alkali-rich photolitic magma in its summit crater. The resultant data should enhance the collec- This makes Erebus one of the few volcanoes on tion of earthquakes that we are using in a com- Earth with nearly continuous, small explosive puter model of the interior of the volcano, as activity and internal earthquake (seismic) activity. well as provide a tool scientists can use for As such, it provides the ideal natural laboratory volcano surveillance, eruption monitoring, and to study these phenomena: How gas is given off for detecting subtle changes in the internal by magma, and the seismic activity that results behavior of volcanoes. The broadband data will from a convecting magma conduit. support a detailed study of the explosion mech- This project entails a combination of seismic anism, especially the very-long-period signals they studies and gas emission rate measurements, emit. It should also help us detect temporal and designed to elucidate the nature and dynamics spatial variability in earthquake mechanisms, of the magmatic plumbing system, as well as which in turn might provide more insights into how eruptions and degassing from the lava lake. variations in gas emissions may be implicated. The gas studies will provide some of the first (GO-081-O) data available on carbon dioxide degassing from a highly alkalic magma system. They Global positioning system should also help to evaluate how much lead measurements of crustal from Mount Erebus (relative to lead released motion in Antarctica. by marine aerosols) gets into the snow on the Barclay Kamb, California Institute of East Antarctic Ice Sheet, and thus shed light on Technology, and Carol Raymond, Jet hypotheses about the anthropogenic origins of Propulsion Laboratory. lead. Further goals of the gas studies are to: Geodesy is the mathematically-grounded • examine the role of Erebus as a source of gas science of using measurements to map the and aerosols to the antarctic environment; positions and shapes of the Earth’s surface • understand the role of volcanism as a features. The satellite-based global position- source of carbon dioxide emissions to the ing system (GPS) has revolutionized the atmosphere, especially for a highly alkalic techniques and enhanced the accuracy of magma; geodetic work. This project has established • understand the evolution of the main a geodetic network in the Transantarctic volatile substances (water vapor, carbon Mountains of Antarctica to measure both dioxide, total sulfur, fluorine and chlorine) vertical and horizontal crustal velocities: in the Erebus magmatic system, as well as their role in the eruptive behavior of • The vertical crustal velocities measured by Erebus; and GPS reflect the viscoelastic response of the • correlate the nature of the gas emissions solid Earth to antarctic deglaciation. That with the observed seismic activity. data will enable us to evaluate discrepancies between models that describe when antarctic The seismic studies of the volcano will: deglaciation probably occurred: Either in Late Pleistocene-Early Holocene (about 10,000 • add a permanent broadband seismic sta- years ago) or later, in Late Holocene time. tion to the array and update the present These data will also constrain the length of data acquisition system; 41

time over which the antarctic ice sheet disin- rebounding due to reduced ice load from GEOPHYSICSGEOLOGYAND tegrated, and should provide a reconstruction East and/or West Antarctica, or is the current of its changes. If antarcitc deglaciation tectonic motion better explained by Terror occurred in the mid-Holocene, we would Rift or uplift of the Transantarctic Mountains? expect a specific pattern of uplift, near the This project uses Global Positioning System Transantarctic Mountains. This new, high-pre- (GPS) measurements of this region to probe cision GPS geodetic system should be able to for data relevant to this controversy. pin that event within a time span of 4 years. We will also measure ice motion, hoping to • Horizontal deformation induced by develop data that would test models for ice rebound can also be measured; these data flow in the Allan Hills meteorite-concentration help constrain models of present-day region, and help determine whether small gla- changes in antarctic ice mass by monitor- ciers in the McMurdo Dry Valleys are thickening ing how the lithosphere is deformed by or thinning. This aspect of the work requires ongoing glacial loading and unloading. setting monuments into rock and ice, and We predict that horizontal component (the establishing their current position with GPS lithospheric response to ongoing ice-mass receivers; any motion will be detected as the changes) to be an order of magnitude data set is compounded in subsequent years. smaller than the vertical (the viscoelastic Our field activities involve close coopera- response to late Pleistocene-Holocene tion with the U.S. Geological Survey. deglaciation). Conversely, that predicted (GO-084-O) rebound signal should be much larger than the associated tectonic uplift rates. Our Logistics support for global seismic baseline measurements will cross known station at the South Pole. fault lines in the Transantarctic Mountains, Rhett Butler, Incorporated Research and may capture co-seismic motion, in the Institution for Seismology. event of an aseismic slip or an earthquake. Seismology, perhaps as much as any other This autonomous GPS station (AGS) network science, is a global enterprise: The waves sends daily data reports to McMurdo Station, resulting from the Earth’s interior motion can and has been designed as a permanent instal- only be interpreted through simultaneous lation that will continue to monitor motion in measurements at strategic points all over the the region. Advanced processing techniques – planet. To help establish the facilities required such as orbit modeling, troposphere correc- to accomplish this crucial scientific mission, tion, ionosphere correction, and extraction of IRIS (the Incorporated Research Institution for annual and seasonal solid Earth and ocean Seismology) was created in 1985. tidal signals – have been developed to refine IRIS is a consortium of institutions that run the accuracy of these crustal velocity measure- research programs in seismology. Fifty-seven ments, especially for the vertical component. universities are currently members, including (GO-082-O) nearly all U.S. universities that run seismological research programs. IRIS has devel- GPS measurements of rock and oped a 10-year plan to implement the global ice motions in South Victoria Land seismographic network (GSN). In addition to Ian M. Whillans, Terry J. Wilson, and portable stations, the GSN will comprise Clyde C. Goad, Ohio State University. about 100 broadband, digital, wide-dynamic- range stations, designed to broadcast such Southern Victoria Land and its environs that any site on Earth will have real-time appear to contain invaluable evidence about access to the complete global data set. the tectonics of Antarctica and how the ice We will install, maintain, and operate IRIS sheet may have changed. Leading models seismic equipment at Amundsen-Scott South differ on one vital question: Is the continent Pole Station and at Palmer Station, Antarctica. 42

GEOLOGY AND GEOPHYSICSGEOLOGYAND Such capability is essential for seismic studies Previous work throughout the Antarctic (in of Antarctica. The resultant state-of-the-art, areas of the Ross Sea, Antarctic Peninsula, broadband, digital seismic capability contin- and Prydz Bay) has used ice shelf deposition- ues the National Science Foundation effort al models to discern the timing of ice shelf to improve seismic instrumentation globally, retreat/advance. This research should build and will provide a crucial link in the GSN. on that data and enhance understanding of (GO-090-O and GO-091-O) the dynamics of ice shelf systems and their role in climate oscillations – past and future. Paleohistory of the Larsen Ice Shelf: (GO-096-O) Evidence from the marine record. Acquisition and operation of broad- Eugene W. Domack and Patrick D. Reynolds, band seismograph equipment at Hamilton College. chilean bases in the Antarctic Peninsula region. Over the last 10 years, scientists have Douglas Wiens and Gideon P. Smith, observed a dramatic decay and disintegra- Washington University. tion of floating ice shelves along the northern end of the Antarctic Peninsula. The present-day tectonics and seismological Meteorological records and satellite observa- structure of the Antarctic Peninsula and tions attribute this catastrophic decay to Scotia Plate region are among the most poor- regional warming, measured at nearly 3°C ly understood of any location in the world. during the last 50 years. (The links between This region offers a unique and complex this warming and the global change attribut- geodynamic setting, as illustrated by recent able to the greenhouse effect, however, are changes in the pattern of volcanism and not fully understood.) Such a retreat of float- other tectonic activity. We constitute the U.S. ing ice shelves is unprecedented in historic component of an international effort – using records, but scientists do not know enough a large-scale deployment of broadband seis- about the longer context, and thus are inter- mographs – to study the seismotectonics ested in the natural variability of ice shelf and seismic structure of these regions. systems over the last few thousand years. During 1997 and 1998, a network of 11 broad- The Larsen Ice Shelf provides an excellent band seismographs in the Antarctic Peninsula point of reference for such studies: Located in region and southernmost Chilean Patagonia were the northwestern Weddell Sea along the east- installed and have since been maintained. Data ern side of the Antarctic Peninsula, the shelf return from this project has been excellent, pro- (according to satellite images taken over the ducing some interesting initial results. We need past five years) is undergoing a rapid, cata- to extend these observations, however, because strophic retreat that is unprecedented in his- there have been few larger magnitude regional toric time, leaving vast areas of the seafloor earthquakes and thus internal strain can be pre- uncovered and in an open marine setting. sumed to be increasing, a longer time frame This project of marine geologic research should elicit data on more revealing events. will collect a series of short sediment cores However, instruments from this project are (within the Larsen Inlet and in areas that borrowed from the IRIS-PASSCAL instrument were previously covered by the Larsen Ice pool and must be returned to PASSCAL in Shelf). By applying established sediment April 1999. This project undertakes the trans- and fossil criteria to the cores, we hope to formation of these three temporary seismome- discover and demonstrate whether the ters into semi-permanent stations, and the Larsen Ice Shelf has experienced periods continued seismological investigation of the of retreat and subsequent advance (similar region for 4 years. Washington University to that of the last half century) within the equipment will also be used to operate a Holocene (the last 10,000 years). fourth station, in Chilean Patagonia. 43

Continued operation of these stations some 1,000 more, in national networks not yet GEOPHYSICSGEOLOGYAND should enhance understanding of the seis- integrated into the FDSN. micity of the South Shetland Trench, an This project is developing a passive seismic unusual subduction zone where young litho- network for the antarctic interior. We will sphere is subducting very slowly. The contin- develop and deploy 11 long-term broadband uing collaboration between Washington seismic stations on the continent itself. University and the Universidad de Chile will Because 98 percent of the continent is ice contribute important seismological data to covered, these stations will be installed at the the IRIS data center, as well as to other inter- surface of the ice sheet. The body-wave data national seismological collaborators. thus recorded from regional and teleseismic Such mutual exchanges with other national earthquakes can be analyzed at each station antarctic seismology research programs will for local crustal thickness, lamination, accumulate data from a variety of other pro- Poisson’s ratio (a measure of crustal composi- prietary broadband stations in the region. tion), crust and mantle anisotropy (a measure These data will support seismic studies of of current and former stress regimes), and the upper mantle velocity structure of several identification of rift zones and crustal block complicated tectonic regions in the area, boundaries. In addition, the data from all sta- including the South Shetland subduction tions (including the existing peripheral ones) zone, the Bransfield backarc rift, and diffuse can be used for seismic tomographic analysis plate boundaries in the areas around to detail lateral variations in these properties. Patagonia, the Drake Passage, and along Six of the stations will be installed at exist- the South Scotia Ridge. Such studies should ing automatic geophysical observatory sites provide important constraints on the crustal (in East Antarctica), which will provide heat structure beneath the stations; in turn and power for the data loggers. The remain- improved structural models will help to pin- ing five stations will be established in West point better locations for future instruments. Antarctica, and will be powered and heated (GO-097-O) by wind turbines during the austral winter. (GO-180-O) Antarctic network of unattended broadband integrated seismometers UNAVCO’s global positioning (ANUBIS). system receiver. Sridhar Anandakrishnan, Pennsylvania State Bjorn Johns, University NAVSTAR Consortium. University. UNAVCO, a consortium of 100 international uni- Despite much attention in recent years, the versities and laboratories, joined to promote structure and dynamics of the antarctic crust the use of global positioning system (GPS) for and the composition and geometry of the man- geosciences research. As part of this activity, tle are still poorly understood. Seismology UNAVCO manages a satellite facility at remains the primary method for studying these McMurdo Station and provides equipment and structures, as well as processes in the Earth’s logistical assistance to earth scientists making deeper asthenosphere, but Antarctica lags far use of the (GPS) for research in crustal dynam- behind in the effort to improve global seismic ics, earthquake, volcano, and global change imaging and tomography. On this huge conti- research. In addition to supporting researchers nent, there are only eight broadband seismic in the U.S. Antarctic Program, UNAVCO also observatories. Except for the installation at supports operations at McMurdo Station and South Pole, those stations are along the mar- Taylor Valley. The UNAVCO facility in Boulder, gins of the continent and none are in West Colorado, offers a complete support program Antarctica. By contrast, there are 200 perma- for university-based investigators including nent stations worldwide in the Federation of Digital Seismograph Networks (FDSN), and 44

GEOLOGY AND GEOPHYSICSGEOLOGYAND • preseason planning, axis, may be associated with slow under- • GPS equipment, thrusting of oceanic crust at the South • training, Shetland Trench. Some 140 million years ago • field support and technical consultation, (during the Jurassic-Early Cretaceous), simi- and lar “back-arc” extension is known to have • data processing and archiving. occurred along the entire Pacific margin of the supercontinent known as Gondwanaland. UNAVCO also represents the academic This area has become western South research community, acting as a central America and West Antarctica. clearinghouse for information on the scientif- Then, some 100 million years ago, mid- ic applications of GPS. As a part of its service Cretaceous deformation of these basins initi- to investigators, UNAVCO works to improve ated the uplift that produced the Andes. GPS surveying accuracy by testing GPS Thus, scientists believe that elucidating the equipment and techniques. deep structure and evolution of Bransfield Using GPS, vector baselines between rift could provide a model of crustal precur- receivers separated by 100 kilometers or sor activity that will more fully describe the more are routinely measured to within 1 cen- early evolution of this globally important timeter (that is, 100 parts per billion). UNAV- mountain chain. CO is also able to support researchers in Years of international earth sciences investigations of global, regional, and local research in Bransfield Strait have produced crustal motions where maximum accuracy consensus on important aspects of its geologic (in the millimeter range) of baseline meas- environment. It is a young (probably ~4 million urement is required. GPS measurements years old) rift in preexisting Antarctic Peninsula using portable equipment can be completed crust; continued stretching of this crust results in a few hours or less. Such expediency lends in complex fault patterns and associated vol- itself to research applications in global plate canism. The volcanism, high heat flow, and tectonics, earthquake mechanics, volcano mapped crustal trends are all consistent with monitoring, and regional tectonics. the basin’s continuing evolution as a rift. (GO-295-O) It is also agreed the volcanism is recent and continues to occur along a “neovolcanic” The young marginal basin as a zone centralized along the basin’s axis. key to understanding the rift-drift Multichannel seismic data collected aboard transition and andean orogenesis: Maurice Ewing in 1991 illustrate the following basin-wide characteristics of Bransfield Strait: OBS refraction profiling for crustal structure in Bransfield Strait. • widespread extension and faulting, James A. Austin, Gail L. Christeson, Ian W. • the rise of crustal diapirs or domes Dalziel, and Yosio Nakamura, University of associated with flower-shaped normal- Texas, Austin. fault structures, and • a complicated system of fault-bounded Bransfield Strait (in the northern Antarctic segments across strike. Peninsula) is one of a small number of modern basins that may be critical for under- The geophysical evidence also suggests standing ancient mountain-building process- northeast-to-southwest propagation of the es. The Strait is an actively-extending margin- rift, with initial crustal inflation/doming fol- al basin in the far southeast Pacific, situated lowed by deflation/subsidence, volcanism, in an inactive volcanic arc between the and extension along normal faults. Antarctic Peninsula and the South Shetland Islands. Widespread crustal extension, Although Bransfield Strait exhibits geo- accompanied by volcanism along the Strait’s physical and geologic evidence for exten- 45

sion and volcanism, continental crust frag- Glacial history of the Amundsen Sea GEOPHYSICSGEOLOGYAND mentation in this “back-arc” basin is still shelf. underway, and has yet to generate ocean Thomas Kellogg, Davida Kellogg, and David crust. Instead, the Bransfield rift lies near Belknap, University of Maine. the critical area that marks the transition from intracontinental rifting to seafloor- The West Antarctic Ice Sheet (WAIS) is the last spreading. Because the basin is asymmetric marine-based ice sheet in the world, and may and appears to manifest shallow be inherently unstable. The limited marine intracrustal detachment faulting, it is near geological and geophysical data available the edge of the spectrum of models to from the Amundsen Sea suggest that ground- explain how continents break up. As such, ed ice or an ice shelf occupied the inner the region is an excellent “natural lab” for Amundsen Sea embayment until perhaps studying the diverse processes that form 1,000 to 2,000 years ago, and this ice may continental margins. have retreated rapidly since then. Organized Thus some significant questions arise: inquiry has been formalized with the WAIS sci- What stage of evolution is the Bransfield rift ence plan. Their Priority Goal H2 asks: experiencing? Does it provide a basis for con- “What is the deglaciation history in the structing models of Andean mountain-build- eastern Ross, the Bellingshausen and ing? The answers are to be found by defining Amundsen Seas?” Bransfield rift’s deep crustal structure. This This project responds to the last of these research work will begin this task by collect- targets by undertaking a study of the marine ing and analyzing high-quality, high-density geology and geophysics of the Amundsen ocean bottom seismometer (OBS) profiles Sea continental shelf from 100° W to 130° W. both along and across the Strait’s strike. Unlike other embayments in West The scientific objectives are to: Antarctica, major ice streams draining into the Amundsen Sea from the interior of the • develop a detailed seismic velocity model WAIS lack buttressing ice shelves. Analysis of for this rift; the distal portions of these ice streams (Pine • calibrate velocity structure and crustal Island and Thwaites Glaciers) indicate glacial thickness changes associated with pre- mass is either in balance or may be dissipat- sumed northeast-to-southwest rift propa- ing. Because both ice streams have beds that gation, as deduced from the multichannel slope downward toward the center of the ice seismic interpretations; sheet, grounding-line recession resulting • document the degree to which deep veloci- from either continued thinning or sea-level ty structure corresponds to along- and rise could trigger irreversible grounding-line across-strike crustal segmentation; and retreat, leading to ice-sheet disintegration. • assess structural relationships between If this ice sheet were to melt, the rise of sea the South Shetland Islands “arc” and level around the globe would follow. Bransfield rift. This project will examine bathymetric data of the Amundsen Sea continental shelf to The OBS data we expect to collect will also determine the positions of former ice-steam be integrated with other geophysical explo- channels, and to help select optimal sites rations of the region (such as both Ewing pro- from which to obtain sediment cores. Single- files). This piece of the puzzle will complement channel seismic reflection studies will also ongoing deep seismic analysis of Antarctic help identify sites for coring, and will locate Peninsula crust to the southwest, as well as and identify morphologic features indicative additional OBS monitoring for deep earth- of former grounded ice (e.g., moraines, quakes. Ultimately, the complex plate tectonic scours, flutes, striations, till wedges and evolution of this region may be clarified. deltas). The coring will be concentrated (GO-306-O) along former ice flow-lines. Core samples will 46

GEOLOGY AND GEOPHYSICSGEOLOGYAND be analyzed in the laboratory for sedimentology, to look for basal tills (indicating former grounded ice and its former extent), and for calcareous and siliceous microfossils. The chronology of grounding-line and ice-shelf retreat from a presumed position during the Last Glacial Maximum near the shelf break will be established, using accelerator mass spectrometry (AMS) carbon-14 dates of acid- insoluble particulate organic carbon. This project shares ship time in the Amundsen Sea with a project in physical oceanography. Our marine geologic data and collected samples – together with the findings of other investigators – should provide another important step toward a comprehensive interpretation of the history of the WAIS. (GO-307-O)

Support Office for Aerogeophysical Research (SOAR). Donald D. Blankenship, University of Texas at Austin.

The Support Office for Aerogeophysical Research (SOAR) was established to facilitate aerogeophysical research over continental Antarctica, by abetting research efforts to understand the dynamic behavior of the ice sheet and the nature of the underlying lithosphere. SOAR uses high-precision laser altimetry to develop data on gravity, magnet- ics, and navigation. SOAR also provides information essential to selecting sites for ice coring in West Antarcta, as well as locations for over-snow seismic transects. This type of interdisciplinary yet focused research and support represents a unique part of the U.S. Antarctic Program, and could revo- lutionize how earth science and glaciology research is conducted in Antarctica. (GS-098-O) 47

THE CAPE ROBERTS PROJECT Cretaceous-Paleogene foraminifera INTERNATIONALROBERTSPROJECT DRILLING CAPE This joint venture brings together the national of the Victoria Land Basin (Cape antarctic programs and scientists from Roberts Project). Australia, Germany, Italy, New Zealand, the Peter-Noel Webb, Ohio State University. United Kingdom and the United States of America. The aim is to recover and analyze Fossils recovered from Cape Roberts Project cores from the sedimentary strata beneath the (CRP) cores contribute to scientists’ ability sea floor off Cape Roberts, in the southwest to reconstruct the ancient prehistory of the corner of the Ross Sea, Antarctica. Geologically region. Foraminifera are marine protozoa with the strata to be drilled are located just within a calcareous shells, one of the basic species major rift – the West Antarctic Rift System – found in the region. The drill may provide cores and have also been close to the South Pole for that aggregate to about 1,500 meters in depth, the last 130 million years. They are over 1,500 which indicate ages from 30 to about 100 meters (m) thick, and were laid down between million years (Late Cretaceous/Paleogene). 30 and more than 100 million years ago. This interval of geological time has yet to be Normally, strata from that long ago (Mid- documented by in situ stratigraphic sections Cretaceous to Paleogene) are deeply buried, in either the Ross Sea or East Antarctica. but strata from the sea floor off Cape Roberts The final disintegration of Gondwanaland record old glacial and rifting events at or near occurred during this time frame, as New the surface. Operations are designed to recov- Zealand and Australia moved north, away er a complete core representing the target from Antarctica. Foraminifera from the CRP 1,500 m of strata; drilling for cores at three drill holes should contribute to an under- separate locations will accomplish this, with standing of the paleogeography and paleo- the depth of individual excavations up to 700 ceanography of a number of significant struc- m below the sea floor. Curators cut the aggre- tures: The highlands and Pacific margin of gate core into 1 m lengths, describe them in East Antarctica (the location of the proto- geological detail, and then photograph them. Transantarctic Mountains), the west antarctic Samples are then distributed to researchers rift system basins and the highlands of West for a wide range of analyses – from extracting Antarctica. This will help scientists recon- specific target fossils to determining more pre- struct the history of the marine margin of cise age and composition data for the sample. East Antarctica (the region near the drill The cores should help scientists answer holes), and decide among current, contend- two important questions: ing hypotheses: Was it located in a Cretaceous cul-de-sac; or did it occupy (at • Before the glaciations of the last 36 million times) a position on a major oceanic circula- years, were there ice sheets on Antarctica tion pathway between the southwest Indian, that may have caused fluctuations in southwest Pacific, and southwest Atlantic world-wide sea levels? Oceans? • How and when did the rifting of the By developing a comprehensive accounting Antarctic continent contribute to the for- of foraminifera – presence, abundance, mation of the Transantarctic Mountains preservation, species dominance and diversi- and the Ross Sea? ty, stratigraphic distribution, levels of endemism or cosmopolitanism in faunas, Developing scientific models to answer and completeness or fragmentation of popu- these questions should provide more general lation structures – we hope to provide data insight into the etiology of changes in global that can be used to address a variety of geo- sea level, as well as the origins of mountains logical problems: and basins. 48

CAPE ROBERTS INTERNATIONALROBERTSPROJECT DRILLING CAPE • We will date disconformities and acoustic and Engineering Center (CSEC) at McMurdo reflectors, which we expect to encounter in Station for further, immediate analysis. As the drill hole, as they extend across the rift drilling operations continue and siting deci- system basins. sions must be made, this age-and-paleoenvi- • We will use benthic foraminiferal bathy- ronmental data is quickly available and can metric indicators to deduce major basin be a valuable part of such decision-making. subsidence/uplift trends resulting from Each season, a preliminary biostratigraphic/ compaction and/or rift margin faulting. paleoenvironmental report based on siliceous • We hope to document phases of transgres- microfossils is produced, and becomes incor- sion and regression, based on more subtle porated into the CRP Initial Reports volume, cyclicity in the stratigraphic distribution along with preliminary results from other of benthic species. These, in turn, may microfossil groups, as well as lithostratigraphic, indicate a relationship between sea level magnetostratigraphic, and other analyses. oscillation and terrestrial glacial events. (GL-051-O) (GL-049-A and GL-049-B) Downhole logging for the Cape Diatom biostratigraphy and paleoen- Roberts Project. vironmental history of Cape Roberts Richard Jarrard, University of Utah. Project cores. David Harwood, University of Nebraska at Through continuous-core and downhole log- Lincoln. ging at the Cape Roberts Project (CRP) scientific drill holes, this project produces geophysical Diatoms are unicellular algae well represented well logs that reveal variations in mineralogy in the fossil record because of their silicified and porosity through time. Geophysical log- cell walls that persist as skeletons after death. ging is essential to producing the basic strati- Analyses of these and other siliceous micro- graphic framework on which all of the other fossils in Cape Roberts Project (CRP) cores are scientific work depends. This is accomplished fundamental to an integrated biostratigraphy by integrating our detailed one-dimensional for the late Cretaceous/Paleogene age (30 records for each hole with available high-reso- million to 100 million years ago), a time period lution seismic data; the result is a fine-grained, not well documented in the southern high two-dimensional interpretation of the core’s latitudes. Diatoms, for example, can provide stratigraphy. This spatial/temporal framework evidence of environmental changes in water then becomes the context for scientists from depth, primary productivity, and the presence several disciplines to locate their own data in or absence of sea ice. CRP cores will provide space and time, facilitating studies of climate, an excellent opportunity to study diatom tectonics, and sea-level change and helping to evolution, including adaptations made in pinpoint the onset of antarctic glaciation. response to strong polar seasonality. (GL-055-O) CRP studies also provide a useful point of contrast and comparison for similar studies Calcareous nanofossil biostratigra- based in the Arctic. Data on Paleogene phy and paleoenvironmental history siliceous microfossils found in Arctic strata of the Cape Roberts Project cores. (for example, Ocean Drilling Program Leg James J. Pospichal and Sherwood W. Wise, 151) can be assimilated with our results to Florida State University; and David Watkins, develop a wider perspective on Paleogene University of Nebraska. high-latitude phytoplankton evolution. This project begins with field-based pale- Calcareous nanofossils are an important ele- ontologic analysis of siliceous microfossils ment in the Cape Roberts Project (CRP), since retrieved from Cape Roberts cores. Core sec- their biostratigraphic record spans the entire tions are then ferried to the Crary Science time interval revealed in the CRP cores. 49

Recent work from other ocean drilling sites and more fine-grained spatial and temporal INTERNATIONALROBERTSPROJECT DRILLING CAPE around Antarctica on this species has allowed record. scientists to produce a refined zonation While other researchers examine the sedi- model for the Southern Ocean. Hemipelagic mentary cores for fossilized fauna and other and pelagic sediments recovered by the CRP elements, this project is solid geology – initial can immediately be placed within this high- description and sedimentological characteri- resolution biostratigraphic framework. By zation of the successive layers, defining and combining these results with data from other constructing facies sequences, and interpret- fossil groups, with magnetostratigraphic ing environments through time when specific data, and with other age-dating methods, depositions were made. The sediments are geological investigators will have a powerful, also subjected to petrologic, petrogenetic, built-in control for dating their results. and initial clay mineralogical analysis. This project supports the drilling program The stratigraphic sections so described then by providing rapid age-and-paleoenvironmen- become points of reference for modeling tal information; as with other allied work, observed marine and geophysical events. sedimentary cores will be studied at the Crary The results also go into the Ocean Drilling Science and Engineering Center (CSEC) at Program-style Initial Report for each drilling McMurdo Station for the target species – season. Combined with information provided in this case calcareous nanofossils – and a by other specialists (such as biostratigraphy, biostratigraphic record of the core published magnetostratigraphy, geophysical logs, and in the Initial Reports volume. geochemical interpretations), these yield an These nanofossils also provide an excel- initial interpretation of the region’s history, and lent paleoenvironmental gauge of surface- provide a foundation for any regional or global water temperature and productivity. Through ramifications that may flow from that history. statistical analysis, a census of their popula- (GL-070-O) tion in an area can tell scientists a lot about the general climate. When combined with Paleomagnetic and mineral magnetic data from other fossil groups and sedimen- characterization of drill cores from tological studies, they provide a lens to the Cape Roberts Project. assess climatic change in the distant past. Kenneth Verosub, University of California at (GL-057-O) Davis; and Gary Wilson, Ohio State University. Initial sedimentological characterization of the Late Cretaceous-Early Over time, the magnetic polarity of the Earth is Cenozoic drill cores from Cape dynamic, and periodically reverses altogether. Roberts, Antarctica. This change in turn affects magnetized and Lawrence Krissek, Ohio State University; and other particles in the earth; over long, ancient Ross Powell, Northern Illinois University. time frames (paleo) the study of these changes – paleomagnetic stratigraphy – combined with The Cape Roberts Project (CRP) aims to pro- the appropriate mineral magnetic studies, can vide new data about the development of the produce an age record of the region. west antarctic rift system, the subsidence The integrated science plan for the Cape history of the Ross Sea, and ice-sheet fluctu- Roberts Project (CRP) entails delivering the ations on Antarctica through a critical time cores to McMurdo Station, where all of the ini- interval for which not enough is known. tial scientific characterization of the cores will Previous work has, however, successfully be done, including magnetostratigraphy, bios- documented the development of the region tratigraphy, petrography, mineralogy, and sedi- and its environmental history. But CPR can mentology. A primary output of this initial work now draw upon newly compiled geophysical is the age of the strata in the cores, because a databases, and hopes to produce a sharper temporal framework is fundamental to the his- 50

CAPE ROBERTS INTERNATIONALROBERTSPROJECT DRILLING CAPE tory of climatic and tectonic events. The on-site fractures that may have been reactivated by magnetic studies of this project will: contemporaneous geologic and tectonic events. • undertake logging of the whole-core mag- The stress data should produce answers to netic susceptibility, which will help corre- a number of questions relevant to the paleo- late the several overlapping cores to be and neo-tectonic evolution of the Antarctic recovered during the CRP; Plate. A number of seminal, outstanding • determine a magnetostratigraphic frame- issues may be resolved; such as: work for dating the cores; • undertake mineral-magnetic and environ- • the cause of the anomalous aseismicity mental-magnetic studies to assess the of the continent, reliability of the paleomagnetic signal; • the geometry of stresses along the lithos- • determine if environmental magnetic pheric boundary between the properties yield information concerning Transantarctic Mountains and the west changes in the tectonic, sedimentologic, antarctic rift system, and diagenetic, or climatic influences on the • the evolution of the antarctic intraplate sedimentary record at Cape Roberts; and stress field and its relation to rifting • undertake detailed environmental and episodes associated with the breakup mineral magnetic studies to evaluate how of Gondwanaland. well the sediments actually record the geomagnetic field. Current stress data obtained from this research will be added to the global stress Ultimately, the CRP records provide the database, helping to fill out the sketchy potential to obtain rare, high southern latitude global stress evaluations associated with constraints on geomagnetic field behavior. the Antarctic Plate. Paleomagnetic studies should also provide (GL-079-O) important data concerning crustal movements and rift development in the Ross Sea sector. Initial palynological characterization (GL-075-O) of Cape Roberts drill cores. Rosemary Askin, Ohio State University; and Stress field history, Cape Roberts, John Wrenn, Louisiana State University. Antarctica. Terry Wilson, Ohio State University. Palynomorphs – both marine (dinocysts) and nonmarine (spores, pollen) types – have The Cape Roberts Project (CRP) is providing proven invaluable for constructing the bios- the opportunity to develop the first age-cali- tratigraphic and paleoenvironmental record brated stress-field history within the west in Antarctica. They record extensive and antarctic rift system of Antarctica. The drill diverse geologic information, and are pre- site, (not coincidentally) located along the served in a wide variety of lithofacies formed margin between the uplifted Transantarctic in various paleoenvironments. Mountains and the rifted crust of the Victoria This collaborative project with New Zealand Land basin, is expected to yield information palynologists will provide initial palynological on the paleostress history of the Mesozoic characterization of the Cape Roberts Project and Cenozoic rift-basin fill material through (CRP) drill cores. Our analyses provide con- analysis of the core, and from downhole log- straining data for an integrated biostratigraph- ging of natural fractures and faults. ic and paleoenvironmental framework, based To establish the stress state contemporane- on all microfossil groups present. Such a ous with any particular stratigraphic level, framework should be of use to all future geo- researchers in this project will examine the logic, geophysical, and paleontologic studies cores for coring-induced stress fractures; and conducted on the cores and in the drilling area. also the borehole (with a downhole televiewer (GL-080-O) and dipmeter) for any wellbore breakouts and 51

GLACIOLOGY PROGRAM geology undertaken by the U.S. Antarctic GLACIOLOGY Ice is the defining characteristic of Program, especially more geologically recent Antarctica, indisputably. The entire continent events during the last 3 million years (with a few exceptional areas such as the (between the Pliocene and Recent epochs). McMurdo Dry Valleys and some lakes and mountains) is covered by a “sheet” of ice Initial examination of the 500,000- that has been laid down over eons, if the year climate record at Mt. Moulton, term sheet can be used to describe a dynam- West Antarctica ic mass several thousand meters (m) thick, Nelia W. Dunbar and William C. McIntosh, larger than most countries, rising over 2,000 New Mexico Institute of Mining & Technology. m above sea level (peaking in an ice dome in the east nearly twice that high), and heavy Geologists crave opportunities to examine enough to depress the bedrock beneath it the vertical face of any significant structure, some 600 m. Actually there are two sheets: since moving down through the horizontal The East Antarctic Ice Sheet is much the larg- layers exposes clues to the history of the er, covering the bedrock core of the conti- region. One such opportunity presents itself nent. The smaller West Antarctic Ice Sheet at Mt. Moulton in West Antarctica, where overlays a group of islands and waters. a summit crater presents 600 meters of The Glaciology Program is concerned with exposed ice, in which can be seen intercalat- the history and dynamics of the antarctic ice ed layers of tephra, the solid material (espe- sheet; this includes research on near-surface cially ash) that is ejected into the air during snow and firn, floating glacier ice (ice a volcanic eruption. shelves), glaciers, ice streams and continen- Using the Argon-40/Argon-39 technique, tal and marine ice sheets. These species of scientists provisionally believe the tephra ice facilitate studies on ice dynamics, pale- layers range in age from 15,000 to 480,000 oenvironments (deduced from ice cores), years; they appear to have originated in a numerical modeling, glacial geology, and nearby volcano, Mt. Berlin. In this 2-year remote sensing. Some current program project, we will revisit the Mt. Moulton blue objectives include: ice site for detailed sampling of the ice section and associated tephra layers, which will be • correlating antarctic climatic fluctuations subjected to geochemical analysis to further (from ice core analysis) with data from arc- refine the dates. Examination of the ice should tic and lower-latitude ice cores; help to determine climatic variations in West • integrating the ice record with the terrestrial Antarctica over the last 500,000 years. and marine records; Our data should supplement that to be • investigating the physics of fast glacier gleaned from the proposed west antarctic flow with emphasis on processes at glacier deep ice core, though ours could potentially beds; yield a much longer climatic record. • investigating ice-shelf stability; and (IO-151-O) • identifying and quantifying the relationship between ice dynamics and climate change. These topics come together in the multidis- Ice dynamics, the flow law, and vertical ciplinary West Antarctic Ice Sheet program strain at Siple Dome. (WAIS), a major initiative of the Office of Polar William Harrison, University of Alaska, Programs. The WAIS program – by developing Fairbanks. an understanding of its history, current state, internal dynamics and its coupling to the cur- Iceflow near a divide such as Siple Dome is rent global climate – is hoping to perfect unique because it is predominantly vertical. models to predict the ice sheet’s future As ice is deformed vertically, the vertical behavior. The Antarctic Glaciology Program strain rate dominates, and must be known in also supports much of the land-based glacial order to calibrate dynamic models of iceflow. 52

GLACIOLOGY This 3-year project – a collaboration between • snow-pit and ice-core studies show layers the Universities of Alaska, Washington and where re-freezing of sufficient liquid water UC-San Diego – will measure the vertical has caused a visibly distinct layer to form. strain rate (as a function of depth) at two sites on Siple Dome, Antarctica. We hope to Each approach is different, and they are develop a better analysis of the ice core than presently not well calibrated to one another. was possible from recent coring sites in cen- We hope to determine how the different tral Greenland. measures of melting may be correlated, We plan to use two relatively new, high-res- using a combination of techniques: Snow-pit, olution systems for measuring the core in hot- ice-core, AWS, remotely sensed data, and water drilled holes. These data, coupled with experiments on melt generation. By looking a determination of the flow-law, will be used at a variety of records of past surface melting to interpret the shapes of radar internal layer- events in Antarctica, we hope to develop a ing as indicators of the accumulation patterns context that will pinpoint especially high and dynamic history of Siple Dome over the temperatures. With all of this data, we hope past 10,000 years; an improved model should to develop a model for a seasonally resolved emerge. This model will then provide a con- paleothermometry, based on a joint text in which to interpret the ice core drilled at approach to measuring ice melt, as well Siple Dome: Both the thicknesses of the annu- as complementary paleothermometers such al layers (as indicative of annual accumulation as borehole temperature, and isotopes. rates) and the borehole temperatures. (IO-168-O) (IO-164-O) Stress transmission at ice-stream West Antarctic Ice Sheet surface shear margins. melting: Recognition controls and Ian M. Whillans and Cornelis J. van der Veen, significance. Ohio State University. Richard Alley, Pennsylvania State University. Shear margins are areas of particular interest Glaciologists work to discover the history of to glaciologists, providing evidence of how dynamic processes, such as ice melting and the slow accumulation of forces over time climate. For example, surface melting on can create cataclysmic features. Three such polar ice sheets can be said to occur when ice stream shear margins are the object of the temperature increases above some this 3-year project aimed at elucidating the threshold. With data on these parameters, transmission of stress. From measurements scientists try to link observed patterns to of the strain rate, we hope to deduce the net detectable changes in the macro glacial force per unit of ice-stream length transmit- terrain, in hopes of developing models that ted between ridge ice and ice-stream ice. may predict the future of antarctic ice. We hope to: This project focuses on the critical Ross Ice Shelf and Siple Dome regions of West • determine how much of the motion of the Antarctica. There are currently in use several ice streams is controlled from the inter- different procedures to measure melting: stream ridges; • correlate the magnitude of this lateral drag • space-based microwave sensors record the with the driving stress on the ice stream, occurrence of liquid water or refrozen ice and with ice stream width; and layers in the near surface; • determine whether lateral drag support • Automatic Weather Stations (AWS) record can be associated with the margin moving the high temperatures that are linked to laterally. development of liquid water; and 53

For field work, we will use ski-equipped verified and the hypothesis strengthened. GLACIOLOGY Twin Otters to install two remote camps We will also take new measurements of that will each be occupied for about 6 days. the thickness, surface elevation, and velocity The Support Office for Aerogeophysical of the ice, in order to compare the buttress- Research in Antarctica (SOAR) facility will ing impact (of Crary Ice Rise) on ice stream conduct aerial surveys to determine the ice B’s flow with data collected during the 1950s, thickness on the inter-stream ridges, as well 1970s, and 1980s. This part of the study as the ice thickness and surface slope on should yield a time series of change in the the ice streams. The field measurements will WAIS over the last half century. be complemented by repeat images of Ice (IO-173-O) Stream E adjacent to the field site [taken by the french SPOT satellite], to allow velocities High-resolution chronology of mil- in the ice-stream side of the margin to be lennial-scale lake-level fluctuations determined. Comparing these velocities to in the Dry Valleys (Antarctica) from those obtained from the strain-grid surveys will provide an estimate of the amount of uranium-thorium and radiocarbon softening of the ice in the margins. dating. (IO-169-O) Brenda L. Hall, University of Maine.

West Antarctic glaciology. Virtually all research science enhances the V. Robert Bindschadler, National Aeronautic wisdom and experience of the investigator, and Space Administration. but some programs are actually designed around that concept, and targeted at specific The West Antarctic Ice Sheet (WAIS) shows groups of scientists. The Professional patterns of iceflow that are not fully under- Opportunities for Women in Research and stood. One so-called surge hypothesis has Engineering (POWRE) program affords new been put forth to explain the basis of these research and educational enhancement patterns; to test it, two critical questions opportunities for women scientists. must be answered: After a program of study and apprentice- ship designed around specific scientific skills, • Are ice streams B, D, and E currently surging? the principal investigator (PI) will undertake • What has been the buttressing effect of an a study of the fluctuations (on a millennial enlarging Crary Ice Rise on the flow of ice scale) of lake levels in the Dry Valleys of stream B? Antarctica, looking for basic causes of climate change. The primary activity will be testing This 3-year project is addressing these the reservoir effect in order to ensure that the questions by collecting data from the air, chronology of lake-level fluctuations is accu- from space and from the surface. Many of rate. With this data in hand, she will make a the studies of change in West Antarctica comparison study of millennial-scale fluctua- have been based on interpolations and cal- tions in other lakes around the world. culations with large uncertainties. We hope The project was specifically designed to to take advantage of global positioning sys- increase the educational and research skills tem data to minimize field logistic require- of the principal investigator. She will learn ments and develop sharper data. Specifically, the following new information/skills: we plan to obtain direct measures of (expected) thinning in the upper portion of ice • thermal ionization mass spectrometry stream D; as well as repeated satellite image (TIMS) uranium/thorium (U/TH) dating measurements at the heads of ice streams B, with Dr. G. Henderson at Lamont-Doherty D, and E. If these reveal inland migration of Earth Observatory (LDEO) and Oxford the onset area, sustained surging may be University; 54

GLACIOLOGY • millennial-scale climate change with Drs. SOAR laser: Calibration and first W. Broecker and G. Bond, LDEO, and with measurement for ice-sheet change Drs. D. Oppo and L. Keigwin, Woods Hole detection. Oceanographic Institution; Ian Whillans, Ohio State University. • antarctic limnology with Dr. C. Hendy, University of Waikato; and The Support Office for Aerogeophysical • regional climate modeling with Dr. K. Research in Antarctica (SOAR) facility pro- Maasch, University of Maine. vides equipment and analysis for a number of Antarctic projects and researchers. Thus, In gathering data from the Dry Valleys, the its data are ramified through numerous PI will use TIMS, U/TH and accelerator mass studies, and must be verifiably valid. This spectrometric (AMS) radiocarbon dating of 3-year project will evaluate some of SOAR’s lacustrine carbonates. Her knowledge of lim- capability; especially the use of its laser, to nology will help not only to assess the lake generate precise and accurate measure- reservoir effect, but provides a foundation ments of the elevation of the antarctic ice to inquire into the causes of large-scale sheet, and to track ongoing changes. changes in lake level. Likewise, regional cli- Tests will be made in two modes: While the mate modeling will allow her to gain insight aircraft is parked, as well as during flights into the energy balance and wind patterns of over ground-surveyed sites near the aircraft the Dry Valleys region during the last Glacial base camp. Once the laser and other equip- Maximum. ment has been validated and calibrated, we (IO-196-O) will begin a limited program to measure changes over time in the surface elevation of glaciologically interesting sites. The goal is to run a “test case” to demonstrate SOAR’s ability to accurately and precisely determine – and track change in – surface elevation. Thus “vetted,” SOAR will become an asset to all investigators involved in precisely mapping and detecting change in the antarctic ice sheet. (IS-166-O) 55

SIPLE DOME ICE CORING to distinguish annual layers back for at least CORING DOMEICE SIPLE Snow flakes form in the atmosphere and trap 6,000 years. Beyond that, data will still be samples of the cloud water, atmospheric indicative (on a slightly coarser time frame) gases and dust through which they fall. When extending to at least 80,000 years ago. it lands in the accumulation zone of an ice This project provides the background for sheet, the snow is compressed, re-crystal- the Siple Dome drilling program, part of the lized, and builds up in ice layers which can be WAIS program, an effort to understand the as thick as several kilometers. Thus discrete current behavior of the WAIS, and to deci- ice strata can be traced to snow that fell over pher the climate it has been subjected to 100,000 years ago. Analyzing this ice for such back through time. We also provide the work- traces permits scientists to estimate climate ing context for individual scientists to do properties such as the temperature, the snow research on the ice core, as well as establish accumulation rate, circulation patterns of the an office to coordinate the various science general ocean and atmosphere, and the con- activities of the organizations involved in the centrations of greenhouse gases when the project, including the National Science snow fell – in short, a reconstruction of the Foundation (NSF), the Polar Ice Coring Office paleoclimate. Such a model of the ancient (PICO), Antarctic Support Associates (ASA), weather improves our ability to predict how and the National Ice Core Laboratory (NICL). these phenomena may interact in the future; (II-152-O) ultimately, we may be able to control the climate society will experience. We can almost High precision borehole temperature certainly better predict how human activities measurements at Siple Dome, will influence the climate. Antarctica, for paleoclimate recon- The NSF has established the West Antarctic struction and ice dynamics studies. Ice Sheet (WAIS) initiative to investigate the Edwin D. Waddington and Gary D. Clow, influence of the West Antarctic Ice Sheet on University of Washington. climate and sea level change. The WAIS- CORES effort will recover and interpret an ice One of the procedures involved in ice coring core from Siple Dome, Antarctica, and eventu- is high-precision borehole temperature pro- ally plans to obtain a second core from a more filing. By constructing continuous tempera- inland site. These locations were selected to ture logs, scientists can develop data vital to provide climate records that will extend back paleoclimate reconstruction and ice dynam- 80,000 to 100,000 years; cores from two sites ics studies. This project will work in the 1 will permit scientists to separate local and kilometer (km) deep fluid-filled Siple Dome regional influences on the climate record they borehole and in several 160 meter-deep extract from the cores. The current season holes along a 20 km north-south transect will wrap up these activities and complete across Siple Dome. The borehole tempera- scientific evaluation of the cores. ture data will be used to:

Recovery and science coordination of • establish the conductive heat flux across an ice core at Siple Dome, Antarctica. the basal interface of the ice sheet; Kendrick Taylor, Desert Research Institute. • reconstruct the surface temperature history at Siple Dome, using geophysical Siple Dome, located between ice streams C inverse methods, known as borehole and D, is well situated to investigate coastal paleothermometry; climate conditions and the dynamics of the • constrain how thick the ice sheet was dur- Siple Coast ice streams, which drain the West ing the late Wisconsin, the magnitude of Antarctic Ice Sheet (WAIS). Ice accumulates 7 the Wisconsin/Holocene deglacial warming, to 11 centimeters each year. By recovering an and the background geothermal heat flux; ice core to 1,000 meters, we expect to be able 56

SIPLE DOME ICE CORING DOMEICE SIPLE • determine calibration constants for the oxygen-isotope paleothermometer at Siple Dome in the past; and • establish the spatial variability of surface temperature over the last century on the 20 km scale near the main drill site.

We expect the results to provide information needed to assess the short-term stability of the West Antarctic Ice Sheet; also improved estimates of the pore close-off ages in the past, which should in turn provide an improved age- scale for the Siple Dome ice core. Ultimately, this work should enhance our understanding of the magnitude of past temperature changes at this significant southern hemisphere site. (II-171-O) 57

INTERNATIONAL TRANS ANTARCTIC • How do the major oceanic and atmospher- INTERNATIONALTRANS-ANTARCTICEXPEDITION SCIENTIFIC EXPEDITION ic circulation systems (e.g., ENSO) influ- From its original formulation in 1990, the ence the moisture flux over West International Trans Antarctic Scientific Antarctica? Expedition (ITASE) has coordinated the efforts • How and why does climate (e.g., tempera- of scientists from several nations to collect ture, accumulation rate, atmospheric circula- and interpret a continent-wide array of envi- tion) vary over West Antarctica on seasonal, ronmental parameters. This cooperative interannual, decadal and centennial scales? endeavor is geared to produce an improved • What is the frequency, magnitude and description and understanding of environmen- effect (local to global) of any extreme cli- tal change in Antarctica over the last ~200 mate events recorded in West Antarctica? years. These original ITASE scientific objec- • What is the impact of anthropogenic activi- tives have been adopted as key science initia- ty (e.g., ozone depletion, pollutants) on tives by both the International Geosphere- the climate and atmospheric chemistry of Biosphere Program (IGBP) and the Scientific West Antarctica? Committee on Antarctic Research (SCAR). • How much has biogeochemical cycling of In 1996 an NSF workshop was held to devel- sulfur, nitrogen and carbon, as recorded in op a Science and Implementation Plan for the West Antarctica, varied over the last ~200 United States contribution to ITASE (called years? “US ITASE”). Because of the long-standing U.S. research effort in West Antarctica, U.S. Radar studies of internal stratigraphy ITASE chose to focus its activities there. At the and bedrock topography along the U.S. ITASE workshop, participants developed U.S. ITASE traverse. a multi-disciplinary research plan that inte- Robert W. Jacobel, Saint Olaf College. grates different approaches to environmental research: Meteorology, remote sensing, ice The U.S. component of the International coring and surface glaciology, and geophysics. Trans-Antarctic Scientific Expedition (U.S. They established a plan with four phases: ITASE) conducts radar studies to determine the internal stratigraphy and bedrock topog- • In Phase 1 meteorological modeling and raphy of the terrain along the traverses. To remote sensing was used to plan sampling help in the selection of core sites as the tra- strategies in support of U.S. ITASE’s major verse proceeds, the radar provides informa- objectives tion on ice thickness and internal layer struc- • Phase 2 initiates ground-based sampling ture that is immediately available to those over four study areas (corridors). Notwith- working in the field. These data can also be standing the broad spatial sampling of used to site deeper millennial scale cores West Antarctica proposed, the logistic (planned at less frequent intervals along the requirements for this sampling will be traverse) and to provide a context for select- modest and highly efficient. ing the location of the deep inland core • Phase 3 will continue ground-based (planned for the future). In addition to map- sampling at a limited number of key ping the traverse route, radar is used to sites where monitoring is required. examine a grid surrounding each of the core • Phase 4 entails data interpretation and locations, to better characterize the accumu- modeling. lation and bedrock topography in each area. This radar system works as a complement The United States component of ITASE to that operated by the Cold Regions Research (which has established a wide range of gen- and Engineering Laboratory (CRREL). Theirs is eral scientific objectives) is trying to refine a high-frequency radar, most suited to the answers to the following questions: shallower portion of the record down to • At what rate is the mass balance changing approximately 60 meters (m); it can detect over West Antarctica? 58

INTERNATIONALTRANS-ANTARCTICEXPEDITION near-surface crevasses. Our radar system is tion of the major atmospheric circulation sys- most sensitive at depths below 60 m, able to tems affecting the West Antarctic Ice Sheet. depict deep bedrock and internal geological (IU-153-B) layers deep into the ice. (IU-133-O) Snow and firn microstructure and transport properties: U. S. ITASE. Science management for U.S. ITASE. Mary R. Albert and Robert E. Davis, U.S. Army Paul A. Mayewski and Mark S. Twickler, Cold Regions Research and Engineering University of New Hampshire. Laboratory.

Coordinating the effort developed for the Not all valuable data are buried deep within United States component of the International the ice. The microstructure and bulk proper- Trans-Antarctic Scientific Expedition (U.S. ties of snow and firn near and at the surface ITASE) is the Science Management Office control the air/snow/firn transport processes; (SMO). The broad aim of U.S. ITASE is to i.e., how heat, vapor, and chemical species in develop an understanding of the last 200 air are incorporated into snow and polar firn. years of west antarctic climate and environ- Since many of the snow and firn properties mental change. ITASE is a multidisciplinary also affect the interaction of radiation in dif- program that integrates remote sensing, ferent parts of the electromagnetic spectrum, meteorology, ice coring, surface glaciology field measurements provide a valuable and geophysics. To marshal this effort, SMO ground truth “check” for complementary runs a series of annual workshops to coordi- efforts using remote sensing to map the spa- nate the science projects that will be tial variations of snow, firn and ice properties. involved in ITASE. They also establish and This project does the field and lab work to operate the logistics base that supports characterize snow and firn properties along ground-based sampling in West Antarctica. the U.S. International Trans-Antarctic (IU-153-A) Scientific Expedition (U.S. ITASE) traverses in West Antarctica. Our objectives are to U.S. ITASE glaciochemistry obtain field measurements of near-surface Paul A. Mayewski and Loren D. Meeker, [down to 2 meters(m)] snow and firn proper- University of New Hampshire. ties: Surface roughness, permeability, density, grain size, surface-to-volume ratio, and Among the research targets for scientists tortuosity. In the laboratory, firn cores from in the U.S. component of the International as deep as 20 m will be analyzed for these Trans-Antarctic Scientific Expedition (U.S. properties and for their microstructure. ITASE) are the impact of anthropogenic activ- Ultimately, we will develop a transport model ity on the climate and atmospheric chemistry to elucidate the nature of the air/snow/firn of West Antarctica, as well as the variations exchange and firnification process at the in biogeochemical cycling of sulfur and nitro- various sites along the U.S. ITASE traverse. gen compounds over the last 200 years. (IU-155-O) This 5-year project is conducting glacio- chemical analyses of the major anions and Hydrogen peroxide, formaldehyde, cations to be found in shallow and intermedi- and sub-annual snow accumulation ate depth ice cores collected on the U.S. in West Antarctica: Participation in ITASE traverses. The ionic composition of polar ice cores provides one of the basic west antarctic traverse. stratigraphic tools for relative dating. Also, Roger C. Bales, University of Arizona. these data can be used to document changes in chemical-species source emissions, which Atmospheric photochemistry leaves valuable in turn facilitate mapping and characteriza- traces in snow, firn and ice, and it has been verified that the efficiency of atmosphere-to- 59

snow transfer and the preservation of these That can be accomplished through a series INTERNATIONALTRANS-ANTARCTICEXPEDITION components is strongly related to the rate of recording instruments that provide contin- and timing of snow accumulation. Thus the uous records of firn densification and snow firn, as well as the atmosphere, provides the surface elevation change. These altimeters context for data. measure the snow surface elevation transient This project will collect samples along the changes, and provide the data necessary to U.S. International Trans-Antarctic Scientific deduce long-term change rates of ice thick- Expedition (U.S. ITASE) traverses. The wide- ness. The ice motion at drill sites, upglacier ranging extent of these traverses will train topography and upglacier gradients in accu- the scientific lens upon a variety of locations mulation rate will be measured and used to covering much of the West Antarctic region calculate iceflow-induced accumulation rate and reflecting a range of different deposition- variations, which ultimately will refine the ice al environments. core records. Measurements of the concentration of sea- (IU-178-O) sonally dependent species (such as hydrogen peroxide, nitric acid, formaldehyde and stable High resolution radar profiling of the isotopes of oxygen) will be made on these snow and ice stratigraphy beneath samples and fed into a recently developed, the ITASE traverses, West Antarctic physically based, atmosphere-to-snow transfer model in order to elucidate the photochemistry Ice Sheet. that led to the depositons. Steven A. Arcone, U.S. Army Cold Regions (IU-158-O) Research and Engineering Laboratory.

Mass balance and accumulation rate The U.S. component of the International Trans-Antarctic Scientific Expedition (U.S. along U.S. ITASE routes. ITASE) uses high-resolution radar profiling Gordon S. Hamilton and Ian M. Whillans, of the snow and ice stratigraphy beneath Ohio State University. the traverse routes in West Antarctica. This project provides a complement to project One of the basic ways to deduce past climate IU-133-O [where levels below 60 meters (m) variations is to track the accumulation of ice, are the focus], concentrating on the shallow- which gives a measure of the balance of mass er levels of the Earth. Excavating the travers- on the continent. Ice cores from the traverse es can be a hazardous undertaking, made routes of the U.S. International Trans- Antarctic much safer, however by the advanced cre- Scientific Expedition (U.S. ITASE) program vasse detection capability of this system. should provide a broad history of how West A coherent, short-pulse radar with a 400 Antarctica has changed in this fundamental way. MHz antenna will be the primary tool. The This 5-year project is tracking the rate of system allows real-time monitoring in a hori- ice sheet thickening/thinning along the trav- zontally scrolled display, and provides excep- erses by looking at flow lines, ice divides tional vertical resolution – to an order of tens and elevation contours. We will measure of centimeters – to a depth of 50 to 70 m. the vertical velocities of markers buried in Analysis relies on simple data compression subsurface ice, using the Global Positioning (stacking), which reveals subtle deformational System (GPS) and surveying techniques to features as well as long distance trends. determine the precise location of these Isochronal continuity will be interpreted from markers. As these markers move up and reflection horizons between core sites. down, they provide a measure of the change (IU-311-O) in ice sheet thickness, when adjusted for the thickness of snow accumulation directly above them. 60

OCEAN AND CLIMATEAND SYSTEMSOCEAN OCEAN AND CLIMATE SYSTEMS at their boundaries, and the use of chemi- Though it borders the world’s major oceans, cal tracers to oceanic processes across a the Southern Ocean system is like no other range of temporal and spatial scales. in the world, with four times more water than • Sea-ice dynamics: The material character- the Gulf Stream, 400 times more than the istics of sea-ice, from the individual crystal Mississippi River. It is a sea where average level to the large-scale patterns of freezing, temperatures don’t reach 2°C in summer, deformation, and melting. where even the water itself is so distinctive • Meteorology: Atmospheric circulation sys- that it can be identified thousands of miles tems and dynamics, including the energy away in currents that originated here. These budget; atmospheric chemistry; transport Antarctic Bottom Waters provide the major of atmospheric contaminants to the antarc- source of cooling for the world’s oceans. In tic; and the role of large and mesoscale fact, if the earth is a heat engine, Antarctica systems in the global exchange of heat, should be viewed as its circulatory cooling momentum, and trace constituents. component. The climate in Antarctica is also unique, Monitoring Antarctic Bottom Water. linked as it is to the extreme conditions of the Martin Visbeck, Lamont-Doherty Earth land and sea below the troposphere (the inner Observatory region of the atmosphere, up to between 11 and 16 kilometers). This ocean/atmosphere The Antarctic Bottom Water is the coldest environment defines and constrains the (and therefor the densest) natural water to marine biosphere, and in turn has a dynamic be found on Earth, created as ice shelves relationship with the global ocean and with melt into seawater and sink to the bottom. weather all over the planet. Few major energy It occurs in the nether regions of the Southern exchanges on Earth can be calculated without Ocean, separated from the world’s great factoring in these essential antarctic phenom- oceans to the north by the Polar Front – ena. As such, they are both an indicator and a water that provides a virtual barrier to the component of climate change. heat transfer from those more temperate and The Ocean and Climate Systems program less stormy waters. sponsors research that will improve under- The global importance of Antarctic Bottom standing of the high-latitude oceanic envi- Water is linked to its subsequent long jour- ronment, including the global exchange of ney across the ocean floor to the Northern heat, salt, water, and trace elements; there Hemishphere. The patterns and strengths of is also an emphasis on sea-ice dynamics, this current are crucial to the heat balance as well as the dynamic behavior and atmos- of the global ecosystem, for this process pro- pheric chemistry of the troposphere. Major vides crucial oxygen to those seas, as well program elements include: as reducing their temperature to nearly 2°C. This project monitors the outflow of Antarctic • Physical oceanography: The dynamics and Bottom Water from the Weddell Sea into the kinematics of the polar oceans; the inter- Scotia Sea, as it begins its journey northward. action of such forces as wind, solar radia- (OO-124-O) tion, and heat exchange; water-mass production and modification processes; ocean Longwave radiation processes on the dynamics at the pack-ice edge; and the antarctic plateau. effect of polynyas on ventilation. Stephen G. Warren and Thomas C. Grenfell, • Chemical oceanography: The chemical University of Washington. composition of sea water and its global differentiation, reactions among chemical Long-wave radiation [also called infrared elements and compounds in the ocean, (IR) or thermal radiation] is an important fluxes of material within ocean basins and component in the energy balance of the 61

atmosphere. On the antarctic continent radia- Computer Interactive Data Access System CLIMATEAND SYSTEMSOCEAN tion processes dominate the surface energy (McIDAS), a versatile computer-based system budget. In summer the balance is made up for organizing, manipulating, and integrating of four terms – primary solar energy in two antarctic environmental data. It captures the forms (incoming and reflected short-wave flow of meteorological information from radiation), and both emitted and reflected polar-orbiting satellites, automatic weather long-wave radiation. In austral winter after stations (AWS), operational station synoptic the sun sets, the short-wave terms fall to zero. observations, and research project reports. The emitted long-wave radiation varies with McIDAS also receives weather forecasts and temperature; thus the radiation balance at the other environmental data products from out- surface determines the surface temperature. side Antarctica, and acts as a repository for This project entails an experimental study existing archived databases. of long-wave radiation processes near the Developed at the University of Wisconsin surface at South Pole station. We are devel- in the mid-1970s, McIDAS receives meteoro- oping instrumentation capable of high resolu- logical data from various sources: Standard tion measurements of the IR fluxes at the synoptic observations, radiosonde profiles, snow surface – a so-called Fourier Transform satellite-based visible and infrared imagery, Interferometer – that will be deployed in late atmospheric profiles inverted from multi- 1999 and operated through the following aus- spectral scanning sensors, and nonstandard tral winter. Supporting observations will also data such as thematic ozone mapping spec- be made of the temperature and moisture trometer (TOMS) data, synthetic aperture profiles in the lower atmosphere, and of ice radar (SAR) sea-ice information, and the AWS crystals in the atmospheric boundary layer. network observations. The system automati- The research also includes several experi- cally registers, calibrates, and locates (by ments concerning the emission characteris- geographical coordinates) the input informa- tics of snow, of ice crystals in the atmos- tion, providing work station access to the phere, and of greenhouse gases near the sur- combined database. Features available to face. Determining the concurrent environmen- the work station operator include: tal conditions (such as cloud-base altitude, Sectorization, false color, enhancements, temperature and humidity-structure), and the brightness stretching, overlays, looping, and sizes and concentrations of ice crystals, will differencing – all specifically keyed to synop- contribute to the newly developing climatol- tic meteorological research and weather fore- ogy of cloud properties, and should substan- casting. Because the look angles from geo- tially improve how radiation processes are stationary satellites are so low, McIDAS represented in general circulation models. relies primarily on data streams from the (OO-201-O) polar orbiters (AVHRR/HRPT and DMSP). To fully use the power of McIDAS to pro- Antarctic Meteorological Research duce meteorological data in the service of Center: 1996-2000. forecasting and research, data links to facili- Charles R. Stearns and John T. Young, tate communications have been established University of Wisconsin at Madison. with a number of scientific weather facilities world-wide; for example: The Antarctic Meteorological Research Center (AMRC) is one of three research centers in • Australian Bureau of Meteorology (ABOM) the Science and Engineering Technology • University of Wisconsin Space Science and Center at McMurdo Station. It is a major cen- Engineering Center (SSEC) ter for meteorological research, and an ongo- • Fleet Numerical Oceanography Center ing experiment to improve operational syn- (FNOC) in Monterey, California optic (simultaneous atmospheric condi- • European Center for Medium Range Weather tions/weather over a broad area) forecasting. Forecasts (ECMRWF) in Reading, U.K. AMRC relies primarily on the Man- (OO-202-O) 62

OCEAN AND CLIMATEAND SYSTEMSOCEAN Atmospheric oxygen variability in rela- Chlorine- and bromine-containing tion to annual-to-decadal variations in trace gases in the antarctic. terrestrial and marine ecosystems. Reinhold A. Rasmussen and M.A.K. Khalil, Ralph F. Keeling, Scripps Institution of Oregon Graduate Institute of Science and Oceanography. Technology.

Oxygen is the most abundant element on Airborne trace constituents in atmospheric the Earth. Airborne, it comprises about a fifth gases come from both biogenic and anthro- of the atmosphere. But much of the Earth’s pogenic sources. Scientists monitor them oxygen exists in water, rocks and minerals, closely, as they have been implicated in deple- and of course in flora and fauna who recycle tion of the ozone layer over Antarctica as well it directly and as carbon dioxide through the as other alterations of the Earth’s climate. processes of photosynthesis and respiration. This study will investigate the seasonal Thus scientists are interested in measuring trend of trace gas concentrations by collect- the concentration of molecular oxygen and ing a year-long suite of air samples at Palmer carbon dioxide in air samples. This project is Station. Samples will subsequently be ana- part of sample collections being made at a lyzed at the Oregon Graduate Center for a series of baseline sites around the world. The number of trace components, especially data should help to improve estimates of the chlorine- and bromine-containing species. processes whereby oxygen is cycled through- This work should contribute to a better out the global ecosystem, specifically: understanding of the buildup of trace constituents, particularly those of high-latitude • net exchange rates of carbon dioxide with marine origin. biota on land and in the oceans, (OO-254-O) • photosynthesis rates, and • atmospheric mixing rates. South Pole monitoring for climate change: Amundsen-South Pole An important part of the measurement pro- Station. gram entails developing absolute standards David Hofman, Climate Monitoring and for oxygen-in-air, to ensure stable long-term Diagnostics Laboratory, National calibration. We also are conducting surveys Oceanographic and Atmospheric of the oxidative oxygen/carbon ratios of both Administration, Palmer Station. terrestrial- and marine-based organic carbon, (OO-257-O) hoping to improve the quantitative basis for linking the oxygen and carbon dioxide geo- James T. Peters, Environmental Research chemical cycles. Laboratories, National Oceanic and These results are needed to enhance our Atmospheric Administration. understanding of the processes that regulate (OO-264-O) the buildup of carbon dioxide in the atmosphere. They should also contribute to our The National Oceanic and Atmospheric understanding of the change processes – Administration (NOAA) has been engaged in especially climate change – that regulate studies to determine and assess the long-term ecological functions on land and in the sea. buildup of global pollutants in the atmosphere. (OO-204-O) The NOAA Climate Monitoring and Diagnostic Laboratory team will continue long-term measurements of trace atmospheric constituents that influence climate and the ozone layer. 63

These measurements will be enable time- stronger. Scientists deploy bottom pressure CLIMATEAND SYSTEMSOCEAN series analyses of multiyear data records. gauges and similar instruments to determine Phenomena of particular interest are: the fluctuations in the transport of the ACC, • seasonal and temporal variations in green- and to relate it to those in the subtropical house gases, and subpolar gyres and to the wind field over • stratospheric ozone depletion, the southern oceans. • transantarctic transport and deposition, Specifically since 1996, scientists in this • the interplay of the trace gases and research project have collected data to char- aerosols with solar and terrestrial radiation acterize the water mass variability in the fluxes on the polar plateau, and Drake Passage, to describe temperature and • the development of polar stratospheric circulation variability in the Southern Ocean, clouds over Antarctica. and to define the role of the Southern Ocean in the global climate system. This season, Four scientists will work from the using a high-density expendable bathyther- Amundsen-Scott South Pole Station observa- mograph (XBT), we will make expendable tory during the austral summer, and two current/temperature/depth (XCTD) observa- NOAA personnel will stay over the winter tions to measure the seasonal and year-to- (working from the Atmospheric Research year temperature fluctuations in the upper Observatory) to measure carbon dioxide, ocean within the Drake Passage. methane, carbon monoxide, aerosols, chloro- To clearly describe inter-annual and seasonal fluorocarbons, and other trace constituents. changes in upper-ocean temperature, we need Concurrent measurements will be made of closely-spaced, underway XBT and XCTD meas- water vapor, surface and stratospheric ozone, urements to be made on every Laurence M. wind, pressure, air and snow temperatures Gould cruise throughout the year. As the ship and atmospheric moisture. Other personnel crosses the Drake Passage, approximately 60 at Palmer Station also will collect carbon XBT profiles and 12 XCTD profiles (measuring dioxide samples in support of this project. salinity) are made, beginning and ending at These measurements will allow us to the 200 meter bathymetric contour on either determine the rates at which concentrations side of the passage. XBT casts are spaced of these atmospheric constituents change, approximately 1 hour apart, although sampling and will suggest likely sources, sinks, and is more frequent across the Subantarctic, budgets. Our work also includes collaborat- Polar, and ACC fronts, as the water tempera- ing with climate modelers and diagnosticians ture changes more rapidly in these regions. to determine how the rates of change of (OO-260-O) these parameters affect climate. Katabatic winds in eastern Antarctica Drake Passage expendable and their interaction with sea ice. bathythermograph program. Gerd Wendler, University of Alaska, Fairbanks. Ray Peterson, University of California. Katabatic winds are driven by the flow of cold The Antarctic Circumpolar Current (ACC) is dense air down a mountain or glacier slope, a powerful force that drives waters in the especially in regions subject to radiational Southern Ocean; four times as fast as the cooling of the Earth’s surface. These winds Gulf Stream, for example. Wherever the dis- can drive the sea ice offshore and are tance between Antarctica and other conti- responsible for extremely high heat fluxes nents is narrowed – so-called chokepoints from the ocean to the atmosphere. They are such as The Drake Passage off the tip of also implicated in the formation of polynyas South America and the sea regions between – areas of open ocean within sea ice. This Antarctica and the Cape of Good Hope and project continues an international collabora- Tasmania, respectively – the current is even tion (France, Australia and the United States) 64

OCEAN AND CLIMATEAND SYSTEMSOCEAN to study katabatic winds along the coast of CDW. The temperature gradient causes this Antarctica. CDW to mix upward and deliver significant A number of weather stations collect data: amounts of heat both to the base of floating One newly installed station 15 kilometers glacier tongues and to the ice shelf. As a con- inland is sited at a point where atmospheric sequence, the melt rate beneath the Pine wind models predict extremely high average Island Glacier averages ten meters (m) of ice wind speeds; two other strings of existing per year, and some specific local areas lose automatic weather stations will continue twenty m. By comparison, typical melt rates to collect data; one that runs from France’s beneath the Ross Ice Shelf cost it only twen- Dumont d’Urville station inland to Dome C, ty to forty centimeters of ice per year. at an altitude of some 3,200 meters; the This project focuses on the dynamics of other string runs along the coast, including CDW on the Amundsen Sea shelf, specifically stations at Cape Denison and Port Martin, an in the regions of the Pine Island and Thwaites area where the highest average surface wind Glaciers, and the Getz Ice Shelf. Both the Pine speeds on Earth have been recorded – a Island and Thwaites Glaciers move very fast, monthly average of 27.8 meters per second. and have a major influence on the regional Project scientists hope to produce a ice mass balance of West Antarctica. numerical model of the structure of the Specifically, we hope to: region’s atmosphere, which will incorporate a more detailed terrain map as well as a new • delineate the frontal structure of the conti- mesoscale model developed by French scien- nental shelf sufficiently to measure the tists. Another goal is to analyze the forma- major routes of CDW inflow, meltwater out- tion, persistence and size of offshore flow, and the westward evolution of CDW polynyas as a function of wind speed; data influence; from satellite-based active microwave • use that data set to validate a three- imagery (synthetic aperture radar) will be dimensional model (currently under con- combined with the observed meteorological struction) of sub-ice ocean circulation; and data in that analysis. A final application of • refine the estimates of in situ melting on this work is to enlarge the body of informa- the mass balance of the West Antarctic tion being collected by Australian and Ice Sheet. Japanese station networks (to the west of these stations) in hopes of assessing the This research should help to elucidate influence of cyclonic storm systems on the antarctic glaciology by assessing the combined drainage flow along the coast. effect of global change on the antarctic envi- (OO-263-O) ronment. The observational program will be carried out from the research ship Nathaniel B. Circumpolar deep water and the Palmer in February and March, 2000. West Antarctic Ice Sheet. (OO-274-O) Stanley S. Jacobs and Martin Visbeck, Lamont-Doherty Earth Observatory, Operation of an aerosol sampling Columbia University. system at Palmer Station. Gail dePlannque and Colin G. Sanderson, Circumpolar Deep Water (CDW) is a relatively Environmental Measurements Laboratory, warm water mass (+1.0°C or warmer) found U.S. Department of Energy. on the outer edge of the continental shelf; normally it is confined by an oceanic front The Environmental Measurements that provides a barrier to the colder and salti- Laboratory [(EML); a unit of the U.S. er waters of the shelf. In the Amundsen Sea, Department of Energy based in New York for example, the deeper parts of the conti- City] installed an array of instruments at nental shelf are filled with nearly undiluted Palmer Station in 1990: A high-volume 65

aerosol sampler, a gamma-ray spectrometer, observations, will provide the basic data CLIMATEAND SYSTEMSOCEAN and a link to the National Oceanic and from which export values can be derived. Atmospheric Administration’s ARGOS satel- Data gathered in this effort will be enhanced lite system. Sampling data from Antarctica by the historical dataset that CINARE has contributes to EML’s Remote Atmospheric obtained in this area over the past decade. Measurements Program, part of its world- Our work will be carried out in collaboration wide surface-air sampling program. with the State Oceanic Administration (SOA) of (OO-275-O) the People’s Republic of China and the Chinese Antarctic Research Expedition. In addition to Particulate organic carbon production providing time on the antarctic resupply ves- and export in the Indian sector of the sel, the SOA will sponsor the primary produc- Southern Ocean: A United States- tivity experiments on board ship and will provide the supporting hydrographic measure- China collaborative research project. ments. The collaborating American scientists Cynthia Pilskaln, University of Maine at Orono. will provide the hardware for the moored sediment trap and will bring their expertise in mak- The Polar Front Zone, where the cold, dense ing these observations to standards developed waters of the antarctic meet the warmer for the Joint Global Ocean Flux Study. All sam- waters of the northern oceans, is subject ples and data will be shared between the U.S. to major currents and water displacements and Chinese investigators, and the data analy- beneath the sea. Each austral spring, phyto- sis will be carried out jointly. plankton bloom in this region. Scientists (OO-278-O) believe the blooms are driven by nutrient transport brought to the surface, as interme- Antarctic automatic weather station diate and deep water masses are ventilated. Each year, the theory goes, such blooms are program: 1998-2001. the primary source of particulate organic car- Charles Stearns, University of Wisconsin bon (POC) and biogenic silica flux to the at Madison. ocean bottom. But the theory remains to be tested, as no data exist on the amount of par- A network of nearly 50 automatic weather ticulate organic matter that is sinking through stations (AWS) has been established on the the water column. Without such quantitative antarctic continent and several surrounding measurements in this region, the hypothe- islands. These facilities were built to meas- sized relationships between biomass produc- ure surface wind, pressure, temperature and tion and the currents must remain undefined. humidity; further, some of them also track As part of a collaboration between the other atmospheric variables, such as snow University of Maine and the Chinese Antarctic accumulation and incident solar radiation. Research Expedition (CINARE), we will study Their data are transmitted via satellite to a the biological production and export flux of number of ground stations, and put to sever- biogenic matter in response to ventilation of al uses: Operational weather forecasting, intermediate and deep water masses within accumulation of climatological records, gen- the Polar Front Zone. The shipboard work will eral research purposes, and specific support be done aboard the Chinese antarctic resup- of the U.S. Antarctic Program. The AWS net- ply vessel, working off Prydz Bay in the work has grown from a small-scale program Indian Ocean sector. in 1980 into a significant data retrieval sys- The initial phase of our work consists of tem that is now extremely reliable, and has setting out a time-series sediment-trap proven indispensable for both forecasting mooring at approximately 64S 73E. The and research purposes. This project main- biweekly-to-monthly trap samples will be tains and augments the AWS, as necessary. analyzed for their organic constituents and, (OO-283-M and OO-283-P) in conjunction with primary productivity 66

OCEAN AND CLIMATEAND SYSTEMSOCEAN Shipboard acoustic doppler current example, show productivity 50 to 60 times as profiling on Nathaniel B. Palmer and great as that in the open ocean, where iron is Lawrence M. Gould. presumed to be abundantly available. One direct way of probing this problem Teresa K. Chereskin, Scripps Institution of is to examine specific sources of iron. There Oceanography. is a drowned and breached volcanic crater at Deception Island, Antarctica; might the Currents in the Southern Ocean have a pro- hydrothermal discharge from this underwater found influence on the world’s oceans – feature provide sufficient dissolved iron to and therefor upon global temperature and support the regional primary productivity in the planet’s ecosystem – yet some remote the ocean? regions receive little scientific attention. This study will trace the discharge volume, Using doppler (sound wave transmission and its iron concentration, and the flushing rate reflection) technology, this project is explor- of the crater during a cruise of Laurence M. ing upper ocean current velocities and will Gould in November 1999. Since the scientific try to generate a quality-controlled data set mission on that cruise is devoted to the in one such sparsely sampled and remote study of how pelagic and benthic communi- region – a region which nonetheless appears ties respond to the seasonal variations in to play a significant role in global ocean cir- the sea ice cover, it will provide a valuable culation. We will develop and maintain a context for the iron study. shipboard acoustic Doppler current profiler (OO-319-O) (ADCP) program on board the Nathaniel B. Palmer and the Laurence M. Gould, two research ships operated by the United States Record of atmospheric photochem- Antarctic Program. istry in firn at South Pole. This work is part of a long-term science Roger Bales and Joseph R. McConnell, goal to characterize the temporal and spatial University of Arizona. velocity structure in the Southern Ocean. This will entail measuring the seasonal and Scientists are eager to develop models that annual changes in upper ocean currents will expand their knowledge of current, active within the Drake Passage, combining this dynamic processes into the past. One such information with similar temperature obser- process vital to the Earth is photochemistry, vations, and exploring how the heat how the sun’s radiant energy affects conver- exchange varies and how it drives upper sion of oxygen in the atmosphere. By measur- ocean currents. ing and interpreting the hydrogen peroxide, (OO-315-O) formaldehyde, and nitric acid concentrations in the snow and firn at South Pole station, we The influence of hydrothermal dis- hope to develop a credible history of the oxi- charge on coastal ocean dissolved dation capacity of the atmosphere over the last two centuries. We also hope to evaluate iron concentrations at Deception methods that will confirm statistically signifi- Island, Antarctica. cant changes in the concentration of these Anne Sturz, University of San Diego. species over that time. South Pole station is ideal for this work: The Iron plays a crucial role, along with some other extreme cold makes the chemistry relatively trace elements, in fueling biological produc- simple; the NOAA Climate Modeling and tion. Over large parts of the Southern Ocean Diagnostics Laboratory provides a context of inorganic nutrients are under-utilized because high quality meteorological and chemical (scientists believe) some trace element is data; and the station is staffed continuously insufficient, most probably iron. Yet some shal- so that samples can be taken year-round. low regions, within the Bransfield Strait for 67

We will sample air and near-surface snow CLIMATEAND SYSTEMSOCEAN throughout the year; during the summer, we will sample and analyze snow pits and firn cores, and will model the air/snow chemistry to try to explain the observed concentrations in the firn. Also in summer, we will sample two snow pits around the perimeter of the snow stake field intensively (for accumulation observations), a process that will establish markers to maintain time control for stratigraphic and chemical horizons. During earlier work at South Pole and in central Greenland, we have developed and tested physically-based models of air snow exchange of hydrogen peroxide. This project extends that work. (OO-324-O) The National Science Foundation (NSF) funds research and education in most fields of science and engineering. Grantees are wholly responsible for conducting their project activities and preparing the results for publication. Thus, the Foundation does not assume responsibility for such findings or their interpretation.

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