Chapman Conference on the Exploration and Study of Antarctic Subglacial Aquatic Environments (SAE)

Baltimore, Maryland USA 15–17 March 2010

Conveners • Martin J. Siegert, University of Edinburgh (UK) Mahlon C. Kennicutt II, Texas A&M University, (USA)

Program Committee • Robin Bell, LDEO, Columbia University (USA) Jemma Wadham, University of Bristol (UK) Kay Bidle, Rutgers, The State University New Jersey (USA) Sergey Bulat, Petersburg Nuclear Physics Institute (Russia)

Financial Sponsors

The conference organizers wish to gratefully acknowledge the generous support of the following sponsors for their substantial support for this conference.

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Program Book Final.pdf 1 3/3/2010 11:13:14 AM Chapman Conference on the Exploration and Study of Antarctic Subglacial Aquatic Environments (SAE)

Baltimore, Maryland USA 15–17 March 2010

Meeting At A Glance

Monday, 15 March 08.30-09.00Coffee 09.00-09.30Introductions – Session 1 09.30-10.30Keynote Speaker 10.30-11.00Session 1 (cont.) 11.00-11.30Morning Break 11.30-12.30Session 1 (cont.) 12.30-13.30Lunch on your own 13.30-14.30Poster Session 14.30-15.00Session 2 15.00-15.30Keynote Speaker 15.30-16.00Afternoon Break 16.00-19.00Session 2 (cont.) 19.00-21.00Dinner on your own

Tuesday, 16 March 08.30-09.00Coffee 09.00-10.30Keynote Speaker – Session 3 10.00-11.00Session 3 (cont.) 11.00-11.30Morning Break 11.30-12.30Keynote Speaker 12.30-13.30Lunch on your own 13.30-14.30Poster Session 14.30-15.30Session 4 15.30-16.00Afternoon Break 16.00-19.00Session 4 (cont.) 19.00-21.00Chapman Conference Dinner (reservation/prepaid)

Wednesday, 17 March 08.30-09.00Coffee 09.00-11.00Session 5 11.00-11.30Morning Break 11.30-12.30Session 5 (cont.) 12.30-13.30Lunch on your own 13.30-14.30Poster Session 14.30-15.30Session 5 (cont.) 15.30-16.00Afternoon Break 16.00-16.30Panel Discussion 1 16.30-17.00Panel Discussion 2 17.00-17.30Panel Discussion 3 17.30-18.00General Discussion and Concluding Remarks 19.00-21.00Dinner on your own

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Program Book Final.pdf 2 3/3/2010 11:13:14 AM Scientific Program

Time Monday Tuesday Wednesday March 15 March 16 March 17

08.30. – 09.00 CoffeeCoffeeCoffee

Introductions Session.3 Session 5. SAE Project Session 1. SAE as Sedimentary Updates Habitats for Life Records

09.00-09.30Introductions by Co- 3.1Keynote, 5.1 Valery Lukin (RUS) Chairs: MartinSiegert MichaelBentley (790556) (UK) and Chuck (UK) (774090) Russian Plans/Activities Kennicutt (US) Subglacial Lake for Drilling into and Sedimentary Sampling Subglacial Lake Processes and Vostok Sediments: Potential Recorders of Past Climate and Ice Sheet Changes

09.30- 10.00 1.1Keynote, Mark 3.1Keynote (cont.) 5.2 Neil Ross (UK) Skidmore (US) (787435) (788714) Subglacial Lake Microbial Communities in Ellsworth: its History, Antarctic Subglacial Recent Field Campaigns Aquatic Environments and Plans for its (SAE) Exploration.

10.00-10.301.1 Keynote (cont.) 3.2 Eugene Domack 5.3WISSARD (US) (787536) Slawek Tulaczyk (UC Subglacial Lake Santa Cruz) (786551) Environment and The Whillans Ice Stream Facies Revealed by Subglacial Access Larsen BIce Shelf Disintegration Research Drilling (WISSARD) Project: an Integrated Study of Marine Ice Sheet Stability and Subglacial Life Habitats in West Antarctica

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Program Book Final.pdf 3 3/3/2010 11:13:14 AM Time Monday Tuesday Wednesday March 15 March 16 March 17 10.30-11.001.2 Jill Mikucki (US) 3.3 Slawek 5.4 Robin Bell (US) SAE (787606) Blood Tulaczyk (US) (799998) Falls, Antarctica: (799325) Melt and Freeze Couplet Insights into Subglacial Formation and in Central East Antarctica Microbial Energetics Preservation of Long- Term Paleoclimatic and Paleoenvironmental Records in Subglacial Lake

11.00-11.30 Morning BreakMorning BreakMorning Break

Introductions Session 4. SAE Session 5. SAE Project Session 1. SAE as Technology Updates (cont.) Habitats for Life Challenges (cont.)

11.30-12.001.3 David Pearce (UK) 4.1Keynote, Peter 5.5 Reed Scherer (US) (802774) The Search for Doran (US) (781456) (787613) Life in Former Subglacial Environmental What Can Tiny Fossils Lake Hodgson, Protection and Teach Us About WAIS Antarctica Stewardship of History & Subglacial Subglacial Aquatic Processes? Environments.

12.00-12.301.4 Jemma Wadham 4.1 Keynote (cont.) 5.6 Sun Bo (CHINA) (UK) (784567) (783170) Examining the Potential Glaciological and for Methanogensis in Geophysical Studies in Antarctic Subglacial Dome A, East Antarctica Aquatic Environments

12.30-12.30 Lunchon your own Lunchon your own Lunchon your own

13.30-14.30 Poster SessionPoster SessionPoster Session

Session 2. SAE Session 4. SAE Session 5. SAE Project Hydrology and Ice Technology Updates (cont.) Sheets Interactions Challenges (cont.)

14.30-15.002.1 Keynote, David 4.2 Matthew 5.7 Robert Marchant (US) Mowlem (UK) Bindschadler (US) Subglacial Floods (788555) (794141) (785500) The Probe Technologies Surprises Seen in the Geomorphic Signature of for The Direct Sub-Ice Shelf Subglacial Floods Measurement and Environment Sampling of Subglacial Lake Ellsworth

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Program Book Final.pdf 4 3/3/2010 11:13:14 AM Time Monday Tuesday Wednesday March 15 March 16 March 17 15.00-15.302.1 Keynote (cont.) 4.3 David Blake 5.8 Christoph Mayer (UK) (787425) The (GER) (787528) Development of a Subglacial Lake Regimes Hot-Water Drill to for Different Lake Access Sub-Glacial Categories Lake Ellsworth 15.30 – 16.00 AfternoonBreak AfternoonBreak AfternoonBreak

Session 2. SAE Session 4. SAE Session 6. General Hydrology and Ice Technology Discussion and Future Sheet Interactions Challenges (cont.) Directions (cont.)

16.00-16.302.2 Adrienne Block 4.4 Michael 6.1 Panel Discussion (US) Gerasimoff (US) #1 – SAE Habitats, (787671) (799480) Hydrology and Ice sheet The Role of Subglacial UW-Wisconsin (ICDS) Interactions-Speakers Lakes in the Onset and WISSARD Drilling from Day 1 Maintenance of Recovery Program: Ice Stream, East Environmental Antarctica Stewardship, Engineering, and Scientific Objectives

16.30-17.002.3 Leigh Stearns (US) 4.5 Bill Stone (US) 6.2 Panel Discussion (787566) (787392) #2 - Sedimentary Subglacial Drainage ENDURANCE: Two Records and Events Under Outlet Missions to Antarctica Technological Challenges Glacier End-members: and Paths to – Speakers from Day 2 Byrd Glacier and Advanced Sub-Glacial Whillans Ice Stream Science Autonomy

17.00-17.302.4 Timothy Creyts 4.6 Alberto Behar 6.3 Panel Discussion (US) (800002) (US) (801014) #3-Future Plans for SAE Drainage of Subglacial The Subglacial Lake Exploration and Research Water Systems Beneath Exploration Device -Speakers from Day 3 Ice Sheets (SLED) Camera

17:30-18.002.5 Jacob Walter (US) 4.7 Ross Powell 6.4 General Discussion (787310) (US) (781228) Concluding Remarks – How Well Do Subglacial Assessing Grounding Co-Conveners Lakes Act as Hydraulic Zones and Sub-Ice- Jacks? Shelf Cavity Processes Using Direct Sampling and Robotic Instrumentation

19.00 -21.00 Dinner Chapman Dinner Conference Dinner On your own (reservation/prepaid) On your own

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Program Book Final.pdf 5 3/3/2010 11:13:14 AM POSTER SESSION SCHEDULE

Poster Session will be held in theHarborview Ballroom, Monday, Tuesday, andWednesday from 13.30 to 14.30.

Achberger, A. Expression of a Bacterial Ice Binding Protein from 3,519 m in the Vostok Ice Core

Barbante Trace Elements and Metalloids in Accreted Ice From Sub-glacial Lake Vostok, Antarctica

Beem, L. High Resolution GPS Measurements Of Ice Surface Velocity Changes On And Around Active Subglacial Lakes, Whillans And Mercer Ice Streams, West Antarctica

Bidle, K. The Use Of Analytical Flow Cytometry And High-Speed Cell Sorting To Assess TheAbundance And Viability Of Ancient Ice Microbes

Bulat, S. Biochemical Study of Lake Vostok Accretion Ice

Carter, S. Taking The Pulse: Laser Altimetry And RadarSounding As A Means To Verify Ice Sheet Water Models At Subglacial Lakes

Christner, B. Biologically and Chemically Clean Subglacial Access Drilling

Cockell, C. Subglacial Life and the Search for Life Beyond Earth

Doyle, S. Evidence for Microbial Metabolism at -15°C in an Antarctic Subglacial Environment

Fricker, H. Synthesising Multiple Remote Sensing Techniques for Analysing Subglacial Hydrologic Systems: Application on MacAyeal Ice Stream, West Antarctica

Hodgson, D. Exploring Former Subglacial Hodgson Lake, Antarctica: Geomorphology, Limnology andPalaeoimnology

Jean Baptiste, P. New Helium Isotope Measurements In The Accreted Ece of The Subglacial Lake

Jiang, J. Scanning Detection Of Multiscale Significant Trend-Changes In Ice- core Records

Langley, KLow-frequency RadarProfiles of the Recovery Lakes

Leitchenkov, L. Potential Proxies Held in Sediment Inclusions From Ice Cores Of The Vostok Station Borehole

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Program Book Final.pdf 6 3/3/2010 11:13:15 AM MacGregor, A. Modeling The Spatial Variation Of Englacial Radar Attenuation: Application To The Vostok Flowline and Implications For The Detection of Subglacial Lakes

Matsuoka, K. Detecting Wet Ice-sheet Beds Across Antarctica Using Radar: A Feasibility Assessment Using Three-dimensional Temperature And Radar Attenuation Models

Pattyn, F. Antarctic Subglacial Lake Discharges

Peters, L. Seismic Imaging Of The Subglacial Plumbing System

Scambos, T. A Sudden Outburst Flood Event BeneathCrane Glacier: Evidence, Causes, andIce Dynamic Effects

Schroeder, D. Comparative Subglacial Hydrology of Thwaites Glacier, West Antarctica, Using Basal Specularity

Siegert, M. Subglacial Lake Vostok: A Review of Geophysical Data regarding Its Physiographical Setting

Takano, Y. Enantiomer-specific Isotope Analysis For Chiral Amino Acids in Antarctic Sub-glacial Environment: Proposal

Takano, Y. Crustal Uplifting Rate Associated With Late-Holocene Glacial-isostatic Rebound at Skallen and Skarvsnes,Lützow-Holm Bay, East Antarctica: Evidence of a Synchrony in Sedimentary and Biological Facies on Geological Setting

Tranter, M. Chemistry of Vostok Accretion Ice And Pore Waters Beneath The Kamb and Bindschadlers Is Consistent With Microbial Life Beneath The Antarctic IceSheet

Vick, T. Microbial Responses During The Transition To Polar Night in Permanently Ice-coveredAntarctic Lakes Trista J. Vick and John C. Priscu Montana State University, Department of Land Resources and Environmental Science, 334 Leon Johnson Hall, Bozeman, Montana, 59717

Vogel, S. On The Role of Subglacial Bio/Geochemical Processes In Global Biogeochemical Cycles-Results From Kamb Ice Stream And ANDRILL

Wright, A. The Identification And Physiographical Setting of Antarctic Subglacial Lakes: An Update Based On Recent Discoveries

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Program Book Final.pdf 7 3/3/2010 11:13:15 AM ABSTRACTS

Molecular and radiation Biophysics, Petersburg Expression of a Bacterial Ice Binding Nuclear Physics Insitute, RAS, St Petersburg, Protein from 3,519 m in the Vostok Ice RUSSIAN FEDERATION; S. Hong,S. Hong, Core Polar Sciences, KOPRI, Incheon, KOREA, REPUBLIC OF; C. Barbante, F. Planchon, P. Achberger, Amanda Achberger Amanda M; Gabrielli, J. Gabrieli, C. Turetta,W. Cairns, G. Brox Timothy; Raymond James A; Doyle Cozzi, IDPA, CNR, Venice, ITALY ShawnM;Christner Brent Craig; Skidmore Mark LA.M. Achberger,S.M. Doyle, B.C. We report here the abundances of 25 elements Christner, Biological Sciences, Louisiana State (Li, Na, Mg,Al, K, Ca, V, Cr,Mn, Fe,Co, Cu, University, Baton Rouge, LA; T. Brox, M.L. Zn, As, Se, Rb, Sr, Mo, Ag, Cd, Sb, Ba, Pb, Bi Skidmore, Department of Earth Sciences, to U) and REE concentration determined by MontanaState University,Bozmen, MT; J.A. ICP-SFMS in the deepest of theVostok ice Raymond, , University of Nevada, Las Vegas, core.The reliable determination of these NV metals and metalloids has been performed in the different types of iceencountered below A bacterium recovered from the Vostok ice 3271 muntil 3659 mdepthcorresponding to core at a depthof 3,519 m wasfound to atmospheric ice, glacial flour and to accreted possess an ice binding protein (IBP) ice originating from the freezing of Lake Vostok homologous to those found in some cold- waters.Fromatmospheric iceand glacial flour, adapted marine bacteria and diatoms. The therelativecontributionsofprimary aerosols IBPs which have been described have been were evaluated foreachelementsusing shown to alterthe freezing and chemical mass balanceapproach in order to recrystallization processes in ice. Comparison provideafirst order evaluation of their of theice crystallinestructure in samples partition between soluble (sea-salt) and frozen with and without the IBP from the insoluble (wind-blown dust) fraction in theice. Vostok bacterial isolate demonstrates its ability Sea-salt spray aerosols are the main source of to alter the ice structure, which could provide impurity to the ice andcontribute largely to cells in the cryosphere with distinct survival Na, Mg and Klevels, and in alesserextentto advantages. Experiments on the temperature- Ca, Sr, Rb, Li and U. For other elements such dependent regulation of the IBP gene indicated as Al, V, Cr, Mn, Fe, Co, Cu, Zn, Mo, Sb, Ba that it was expressed at 4 degrees C, but not andPbas well as thenon sea saltfraction of at temperatures above 10 degrees C. Our Mg,K,Ca, Sr,Rb, Li andU,dustinputsappear results provide evidence for a molecular to primarily control theirdeposition variability. adaptation to icy conditions and for a low ForAs, Se, Ag, Cd andBi, primary aerosols are temperature stress response that appears not consistent with theobservedlevels and distinct from the classical bacterial cold-shock other sources are likely important. For the response. glacial flour, the comparable levels of elements with the overlying atmospheric ice suggest that Trace Elements and Metalloids in Accreted incorporation of abrasion debris at the glacier Ice From Sub-glacial Lake Vostok, sole is limitedin the sections considered. For Antarctica the accreted ice originating from the subglacial Lake Vostok, a contrasting situation is Barbante, Carlo Barbante Carlo; Planchon observed between asolute-richaccreted type- Fridiric;HongSungmin; Gabrielli Paolo; 1 where large aggregates are encountered and Gabrieli Jacopo; Turetta Clara; Boutron solute-poor accretedice type-2 devoid of any Claude; Petit Jean-Robert; Bulat Sergey; visible inclusions. Hong Sungmin; Cescon PAolo;Cairns Warren; Cozzi Giulio C. Barbante, J. Gabrieli, High ResolutionGPS Measurements Of Ice P. Cescon, Environmental Sciences, University Surface Velocity Changes On And Around of Venice, Venice, ITALY; P. Gabrielli, Byrd Active Subglacial Lakes, Whillans And Polar Research Center, The Ohio State Mercer Ice Streams, West Antarctica University, Columbus, OH; F. Planchon, Section of Geochemistry -Geology Department,Royal Beem, Lucas Beem Lucas; Tulaczyk Slawek Museum forCentral Africa, Bruxelles, M; Walter Jake; JoughinIan R; Smith BELGIUM; C. Boutron, J. Petit, LGGE, CNRS, Benjamin Eaton; Fricker HelenAmanda L. Grenoble, FRANCE; S. Bulat, Division of Beem, S.M. Tulaczyk, J. Walter,, University of

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Program Book Final.pdf 8 3/3/2010 11:13:15 AM California Santa Cruz, Santa Cruz, CA; I.R. activity of subglacial lakes, that can be Joughin, B.E. Smith, Applied Physics incorporated into prognostic icesheet models. Laboratory, University of Washington, Seattle, WA; H.A. Fricker, Scripps Oceanographic The Subglacial Lake Exploration Device Institute, University of CaliforniaSan Diego, (SLED) Camera San Diego, CA Behar, Alberto BeharAlberto Enrique A.E. In late 2006 an extensive subglacial water Behar, In Situ Instruments, NASA/JPL, system was discovered beneath Whillans and Pasadena, CA Mercer ice streams, West Antarctica, usingIce Cloud and land Elevation Satellite (ICESat) SLED camera: The Subglacial Lake Exploration laseraltimeter data.Amore comprehensive, Device (SLED) camera is a miniaturized, continent-wide study has now detected more propelled, ice-borehole optical recording device than 120 activelakes. Active subglacial lakes designed to observe the borehole ice are the most dynamic known elements of properties, water-ice >interface, distribution Antarctic subglacial hydrologyand can create of basal debris, suspended particles in > regional-scale changes in the distribution and water columns, and sediment surface pressure of subglacial water, which couldaffect properties. The development of SLED is ice flow rates. Ice streams can go through supported by NASA under a separate Award. largechanges in flow patternsovershort SLED will performthe following functions at periods of time. The Kamb Ice Stream both SLW andthe grounding-line sites: record stagnated very rapidly ~150 ybp. the borehole ice properties,investigate the Observations show Whillans IceStreamis marine iceinterface,examine distribution of slowing and widening. Much of the modulation entrained debris in basal ice, observe geometry of icestreamdynamics is believedto derive of ice-waterinterface;inspectthe water from changes in basal conditions, which column for suspended particles as well as include variations in subglacial water pressure, possible aquatic organisms, search for visual hydrological drainage patterns and thermal evidence of waterstratification and/or regime.The active lakesdetected by ICESat horizontal/vertical motion;investigate the have shownpatterns of filling and draining on sea/lake floor for evidence of erosional and the timescale of just six years (2003-2009), sedimentary processes (glacial flutings, with total basal water flux of multiple km3 a-1 subaqueous sediment failures, debris flows, below the Whillans Ice Stream alone. In late deltas, drainage channels, etc.), record signs 2007, we deployed ten continuous Global of possible bioturbation and/or evidence of PositioningSystem(GPS)receivers directly benthic organisms. Algal mats have been over and proximal to two of the lakesof the observed on the seafloor beneath the recently Whillans/Mercer system: Subglacial Lakes disintegrated Larsen Ice Shelf (Domack et al., Whillans (SLW) and Mercer (SLM). This data 2005) and marine crustaceans at the edge of permits analyses of subglacial lake level the grounded ice of the more open marine variations and coincident velocity fluctuations; environment at McKay Glacier (Powell et al., it also provides a continuous record of lake 1996). In addition to biological exploration, we activity,whereas ICESat only samples twicea intend to use the camera to examine the year. At the time of the Chapman Conference, structures of thesea floor,looking forevidence more than two years of data will have been of groundingzonewedges that may mark the acquired that document surface velocity and historic location of the grounding lineduring elevationchanges in this region.Overthis glacier retreatepisodes (Anderson andShipp, period, SLMhas filledconsistently.Preliminary 2001). We will design thecamera to look up at results provide no clear evidence that surface andacross thebase of the iceshelf. This first- velocity above and adjacent to SLM has been ever view may well reveal aspects of the > significantly influenced by this lake filling. SLW ocean-ice heat and mass exchange processes, filled for at least thefirst 14 months of which may depend on interface roughness. observationand drained in mid 2009;GPS provides the exact timing of the drainage. Melt and Freeze Couplet in Central East Preciseknowledge of SLW’s activity is Antarctica especially important because the lake will be drilled in 2012-2013 by the WISSARD project. Bell, Robin Bell RobinE;CreytsTimothyT; The results of our survey will offer insights into Wolovick Mike; Spector Perry; Studinger the effects of the dynamics of the Whillans Ice Michael; Jordan TomA; Frearson Nick; Stream and the ultimate goal of deriving a Ferraccioli Fausto; Corr Hugh; Braaten David constitutive relationship, which accurately Alan; Damaske Detlef R.E. Bell, T.T. Creyts, describes the dependence of ice stream flow on M. Wolovick, P. Spector, M. Studinger, N.

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Program Book Final.pdf 9 3/3/2010 11:13:15 AM Frearson,,Lamont-Doherty EarthObservatory melt while the strong near-bed reflector is of Columbia University,Palisades, NY; D.A. indicativeoffreezingtothe base of theice Braaten,Centerfor Remote Sensing of Ice sheet. These melt-freeze events likely occur Sheets, Kansas University,Lawrence, KS; T.A. over much longer periods than dynamic Jordan, F. Ferraccioli, H. Corr, , British observations have been made. The widespread Antarctic Survey, Cambridge, UNITED accretion of 100’s of meters of ice to the base KINGDOM; D. Damaske, , Federal Institute for of the ice sheet would have ramifications for Geosciences and Natural Resources, Hanover, ice sheet mass balance, accumulation, ice GERMANY sheet models and the fidelityofice cores.

The Gamburtsev Subglacial Mountains, Subglacial Lake Sedimentary Processes encased in 1-4.5 kilometers of ice, are the And Sediments: Potential Recorders of most poorly understoodmountainrange on Past ClimateAnd Ice Sheet Changes Earth. During theInternational PolarYear, the firstsystematic aerogeophysical survey was Bentley, Michael Bentley Michael; flown over this region and acquired over Christoffersen Poul; Hodgson Dominic; 120,000 line km of laser, radar, gravity and Tulaczyk Slawek M; SmithAndrew; Le Brocq magnetic data.These deeply dissected Anne MM. Bentley, A.M. Le Brocq, mountains ranges are characterized by a well Department of Geography, University of developed alpine valley system with large Durham, Durham, UNITED KINGDOM; P. cirques along the ridge lines. Along the Christoffersen,Scott PolarResearchInstitute, southeasternedge of the Gamburtsev University of Cambridge, Cambridge, UNITED Mountains, along a valley head, the ice sheet KINGDOM; D. Hodgson, A. Smith,, British internallayersare deflected downwardsovera Antarctic Survey, Cambridge, UNITED region 12 km long and 4 km wide. In this KINGDOM; S.M. Tulaczyk,Earthand Planetary valley head, internal layers that are regionally Sciences Department, University of California, over 750m above the ice sheet bed intersect Santa Cruz, CA thebase of theice sheet. This distinctive pulled-down geometry of the internal layers The development of funded programs to drill suggests that up to 20km3 of ice hasbeen into Antarctic subglacial lakes means that there removed at melt ratesup to centimetersper is an imminent prospect of retrieving the first year. Discontinuous bright basal reflectors sedimentsfromanextantlake. These 100-500m long in the valleysuggestbasal sediments are potentially important for at least water in pockets. Any water produced by three reasons. Firstly they may record change basal melt would be driven down the in the conditions at the base of the ice sheet. hydrologic potential to the east into a 20 km Forexample,itispossiblethat thecomposition long2-3.5 km wide east-westtrending valley of subglacial lake sediment may vary on bounded by 150-200m high hills. Along the glacial-interglacial cycles, with varying northern (upflow) side of the valley, a distinct amounts or composition of dust or other internal reflector emerges from the valley wall components of sedimentary input, or episodic in the typically echo-free base of the ice sheet. change from movement of subglacial water. This near-bed internal layer can be clearly Second,some lakesmay preserve non-glacial traced up to 10 km to the south of the valley. sedimentsfromintervals of icesheet retreat or The near-bed reflector is generally found collapse, or from preglacial conditions. In both 150m-700m above the base of the ice sheet these cases a major attraction of using and has amplitudes of 10-30dB. The low end subglacial sediment is that manylakes are of the amplitudes is similar to theinternal thought likely to contain sediments layers at the same depth while the high end of substantially older than therecordprovidedby the amplitude is similar to the reflection from ice cores. The third reason is that the the icesheet bed. We interpret this strong sediments may not only act as a habitat for near-bed reflector as the contrast between the life, particularly at the relativelynutrient-rich meteoric and basal freeze-on (accretion) ice. sediment-water interface, but they may also At the easternend of the east-west trending preserve a record of past life in the form of valley, the bright reflector bulges over the organic goechemicals, including DNA, in the southern edge of the bounding hills. Above sediment. In order to assist future planning, this near-bed reflector bulge, the internal site selection, andidentifying appropriate layers are conformable with thenear-bed analytical techniques,wereview whatisknown reflectorand notthe underlying topography. about sedimentsfromformerlysubglacial lakes We interpret these unusual internal layers as a in Antarctica and elsewhere, including from melt freeze couplet. The drawndowninternal both geophysical data anddirectsampling.We layers point towards theproductionofbasal also discuss what we might reasonably

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Program Book Final.pdf 10 3/3/2010 11:13:15 AM speculateabout theirphysical characteristics that viable 8Myr old bacteria possess from analogies with surface glacier-fed and particularlyeffective and novel DNA repair glacier-contact lakes, andfromknown mechanisms forwhich we can obtain genetic limnological andglaciological processes. This signatures.Our analyses suggest that includes consideration of the three likely main fluorescence staining and flow cytometry pathways for sediment for subglacial lake analysis is feasiblefor microbes encasedin sediment: rain-out of englacial sediment at the ancient ice. We have been able to optically lake ceiling, rain-outofsubglacial sediment discriminatebetween abiotic,glacial till from basal debris layers,and transportof particles and nucleic acid-containing, bacteria sediment by meltwater drainage into the lake. in ourice meltwatersamples upon staining We also discuss the likely sediment-landform with SYBR-Gold or SYTO-13 and ultimately associations that may existalongsubglacial determine the microbial abundance. At the lake margins. From this we develop a sametime, we used flow cytometry to assess conceptual model of subglacial lake ice microbe viability with fluorescent sedimentation, focussing especially on likely LIVE/DEADstainsand relate the percent processes and sediments in lakes Vostok, viability to iceage. We discriminated between Whillans and Ellsworth. Finally, we discuss the activeand dormantbacteria viamarkers for implications of thelikelysediment respiratoryactivity by staining dilute meltwater characteristics for the coring technologies that cultureswith theredox dye5-Cyano-2,3- will be adopted to retrieve such sediment Ditolyl Tetrazolium Chloride (CTC), which is sequences. reducedintracellularlyinrespiringcells to an insoluble, fluorescent precipitate. Based on our The Use Of Analytical Flow Cytometry And sample types (i.e., microbes encased in a High-Speed Cell Sorting To Assess The frozen state for at least 100 Kyr), our results AbundanceAnd ViabilityOfAncient Ice suggest that the maximum recommended Microbes concentration (5 mM)and extended incubation times (24 h) are necessary to detect active Bidle, Kay Bidle Kay; Natale FrankK.Bidle, microbes in these samples,given their F. Natale,Marine andCoastal Sciences, inherently low metabolic rates andgrowth Rutgers University, New Brunswick, NJ rates in situ.

It is currently unknown whether ancient ice Surprises Seen In The Sub-Ice Shelf samples, which have been exposed to harsh Environment environmental conditions, are amenable to flow cytometry andhighspeed cell sorting, Bindschadler, Robert Bindschadler Robert; even though these analytical techniques pose Behar Alberto Enrique; Truffer Martin; several major advantages.For example,they Stanton Timothy P; Kim Stacy R. require small sample volumes (<1 ml) for Bindschadler, , NASA, Greenbelt, MD; A.E. analysis, while yielding extensive information Behar, , Jet Propulsion Laboratory, Pasadena, on cell abundance andphysiological state. CA; M. Truffer, Geophysical Institute, They are also amenable to single cell University of Alaska, Fairbanks, AK; T.P. genomics, which provides unprecedented Stanton,, Naval Postgraduate School, access to the genomic material of yet- Monterey, CA;S. Kim, ,Moss Landing Marine uncultured taxonomic groups, greatly Laboratories, Monterey, CA facilitatingthe discoveryofnovel metabolic capabilities. We applied emerging techniques in We are pursuing the hypothesis that the heat analytical flow cytometryto quantify the total of ocean waters is responsible forincreased ice and metabolically active microorganisms in thinning, retreat and flow acceleration of the Antarctic ice samples ranging 100 Kyr to 8 ice sheet edge in the Pine Island region of Myr, in order to assess the relative proportion West Antarctica. While awaiting sufficient of viable vs. dead cells and to explore genetic logistic support to begin sustained ocean strategies of DNA repair in ancient ice profiling and directly observe the sub-ice-shelf microbes. We recently established that, even environment of the Pine Island Glacier ice after 8 million years of cosmic radiation shelf, our novel methods were tested during bombardment, viable microbes and microbially the 2009-2010 field season in Windless Bight, derived DNAcould be recovered from buried 20 milesnortheast of McMurdo Station, glaciers in the Dry Valleys of the Transantarctic Antarctica. There, an 8-inch diameteraccess Mountains, Antarctica. Given the strong hole was drilled through the 180-meterthick influenceofcosmicfluxonDNA degradationin iceshelf usingarelativelylight and ancient icesamples, we hypothesizethat the transportable hot-waterdrillingsystem. A degree of DNA damage increases with time and borehole camerarevealed the scalloped nature

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Program Book Final.pdf 11 3/3/2010 11:13:15 AM of the melted borehole, obtained what we tested before deliverytoSLE. believe to be the first-ever picturesofthe underside of an ice shelf, and captured videoof TheRoleofSubglacial Lakes in theOnset a Lyssianasid amphipod as it explored our and Maintenance of RecoveryIce Stream, borehole.Uponrecovery, we also discovered East Antarctica what appear to be jelly tentacles on the camera cable.Proof of higher lifeforms more Block, Adrienne BlockAdrienne E; Bell Robin than 20 kilometers from even seasonally open E; Flowers GwennE; Pimentel Sam; water and underneath thick floating ice Studinger Michael; Frearson Nick A.E. Block, suggestamore expansive biological footprint Earthand Environmental Sciences,Columbia in the Ross Sea region than previously held. University, NewYork, NY;A.E. Block, R.E. Initial oceanprofilerdatacollecteduponinitial Bell, M. Studinger, N. Frearson,, Lamont- lowering into the800-meter deep water cavity Doherty Earth Observatory, Palisades, NY; S. confirmexpectedvaluesofsalinity and Pimentel,Department of Earthand Ocean temperature. Subsequent profiles will provide Science, University of British Columbia, more valuable data on the temperature, Vancouver, BritishColumbia, CANADA;G.E. salinity and current structure and how these Flowers, Department of EarthSciences, Simon vary with time, including tidally forced Frasier University, Burnaby,British Columbia, oscillations. CANADA; The Recovery Ice Stream drains 8 The Development of aHot-Water Drill to Access Sub-Glacial Lake Ellsworth Biogeochemical Study of Lake Vostok Accretion Ice Blake, David Blake David MD.M. Blake, Technology & Engineering, British Antarctic Bulat, Sergey Bulat Sergey; Alekhina Irina; Survey, Cambridge, UNITED KINGDOM ChuvochinaMaria; LipenkovVladimir; Lukin Valery; Barnola Jean-Marc; Wagenbach Access to Sub-Glacial Lake Ellsworth(SLE) is Dietmar; De Angelis Martine; Leitchenkov scheduled for the 2012/13 Antarctic summer German L; Marie Dominique; Normand season. Ahot water drill is to be developed to Philippe; PetitJean-RobertS. Bulat, I. produce an initial hole diameterof 36 Alekhina, M. Chuvochina, , Petersburg Nuclear centimetres to enable an instrumented probe PhysicsInstitute,StPetersburg, Gatchina, to enterthe lake. The design of the drill will RUSSIAN FEDERATION; V. Lipenkov, V. Lukin, build on previous concepts and developments , Arctic and Antarctic Research Institute, St used by the British Antarctic Survey (BAS) for Petersburg, RUSSIAN FEDERATION; S. Bulat, hot water drilling in Antarctica. SLE is to the I. Alekhina, M. Chuvochina, J. Barnola, M. De southofthe EllsworthMountains andwith a Angelis, J. Petit, , Laboratory of Glaciology and ground transportation route to a blue ice Geophysics of Environment CNRS, Grenoble, runway at Patriot Hills. For the drilling FRANCE; D. Wagenbach, Institut fur programme at SLE, allequipment, materials Umweltphysik, University of Heidelberg, andfuel will be carried from SouthAmerica to Heidelberg, GERMANY;G.L. Leitchenkov, , Patriot Hills via airborne heavy lift. With a Institute forGeology andMineral Resourcesof maximum aircraft load of 19 tonnes, attention the World Ocean, St Petersburg, RUSSIAN to the maximum size of components andthe FEDERATION; D. Marie, , Station Biologique de overall weight is necessary to ensure materials Roscoff, Roscoff, FRANCE; P. Normand, can be transported by air. The drilling hose at Ecologie Microbienne, Universite Claude over 3200 metres and the winchwill be the Bernard-Lyon I, Lyon, FRANCE largest component needed to be transported as one item.A procedure has been produced and The objective wastoperform complex will be adopted to ensure all of the components biogeochemical study of accretion ice of the are cleaned before they are used at SLE. subglacial Lake Vostok, East Antarctica with Biological filtering will be employed to remove the ultimate goal to discover alien lifein this viruses and product from the water supply. extremeicy environment. Theadditional task The electrical supply, pumps and ancillary was to proveour previous scenario (Bulat et items will be housed in a field camp adjacent al., 2004) by complementary analyses to the access hole. Sufficient fuel is to be includinggas content, dissolved organiccarbon provided in 205 litre drums to support the field (DOC), major ion chemistry, mineralogy of site and enable two separate accesses of the sediments, microbial cell enumeration and 16S lake. The drillis being developed and rRNA genes sequencing.As a result, totalgas assembledatBAS in Cambridge and will be content proved to be 2-3 orders of magnitude lower than in glacier ice. Meanwhile a giant

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Program Book Final.pdf 12 3/3/2010 11:13:15 AM mica-clay sediment inclusionwithin themono- borehole between 3680 and 3690 m. The new crystal lake ice showed an unusual content of accretion ice including the inclusion-rich oxygen,carbon dioxide and methane. Mean ‘thermophile-containing’horizon (Bulat et al., DOClevelswere found to be less than 20 pbb. 2004; Lavire et al., 2006) (around 3608 m) Majorion chemistryshowedenrichment of will again be recovered and its complexity magnesium and calcium sulfates along with studied. The following season (2010/2011) the sulfides in ice with sediment inclusions only. drill will enterthe lake. This entry will be Amongst the latter sulfide minerals like pyrite performed using athermal drill and clean were also identified. Accordingly, possible silicone oil as adrill liquid, which will replace redox couples are rather limitedin supporting the kerosene mix at the borehole bottom. chemolithoautotrophiclife forms. The During the lake entrysensors for oxygen molecular microbiology study constrained by content (and some other parameters) will be Ancient DNA research criteria showed that the invoked to get the initial gas values directly at iceuntil depth 3659 mcontainsthe very low the moment of the contact. In addition, the microbial biomass (Table 1).The only ice lake water will be supposedly sampled into containing mica-clay inclusions allowed the specialwall-warmed bathometersplaced within detection of unusual gascontent andrecovery thedrill to be studiedunfrozeninclean labs. of few bacterial phylotypes all passing The season after (2011/2012) the lake water contaminant controls butnot fittinggroups raised up to dozens meters within the borehole expecting to discover. The latter included the 5G-2 and subsequently allowed to freeze will well-known chemolithoautotrophic thermophile be re-drilled to get sharply frozen lake water (unexpected). In contrast, the deeper (fromdifferent horizons rangingfromdirty at accretion ice with no sediment present and gas thetop to cleanat thebottom) forlater content close to detection limit gave no reliable complexinvestigation. During that season, or signals. Since Antarctic subglacial lake the season after a special set of biophysical environments are thought to analogues for instrumentsdeveloped nowin thePetersburg extraterrestrial icyenvironments,their ability Nuclear Physics Institute (now a member of to support microbial life is willingly considered Russian national research centre for nuclear unquestionable. However, amongst them the physics andnanotechnology-Science, 2009, Lake Vostok can be viewed as very special with 461, 1028) will be sent into the waterbody extremely low biomass giant aquatic body on with abattery of commonocean observatory theEarth, exploration of which is highly prone sensors, visible and infra-red light cameras, to forward-contamination. spectrometers/fluorimeters and special water samplers loadedon a board of several Russian Plans/Activities ForDrillingInto submersibletitan modules, firstly as ROVs And Sampling Subglacial Lake Vostok hooked on a special line and operated with the help of atrollingreel andthen-as AOVs. Such Bulat, Sergey,Bulat Sergey;LukinValeryS. activities will be in a line with environmental Bulat, ,Petersburg Nuclear Physics Institute, stewardship in exploration of uniqueaquatic St. Petersburg, RUSSIAN FEDERATION; V. environments under the thick Antarctic ice Lukin, Arctic and Antarctic Research Institute, sheet. St. Petersburg, RUSSIAN FEDERATION Taking the “Pulse:” Laser Altimetry and The Russian Federation hasdeveloped a RadarSounding As AMeans To Verify Ice national ongoingproject on thedrillinginto, Sheet Water Models At Subglacial Lakes. and samplingof, subglacial Lake Vostok, East Antarctica. Thegoal is to explore this extreme Carter, Sasha Carter Sasha P; FrickerHelen icyenvironment in amultifacetedway,to Amanda; BlankenshipDonald D; Lipscomb identify the form and levels of file that exist William H; Price Stephen F; Johnson Jesse V; there. The project is funded by the Russian Young Duncan AS.P. Carter, H.A. Fricker, Federal Service for Hydrometeorology and Cecil Hand IdaM.Green Institute of Environmental Monitoring (ROSHYDROMET) Geophysics andPlanetary Physics, Scripps and is available for open for collaboration. In Institution of Oceanography, UC SanDiego,La the season 2009/2010 drilling operations will Jolla, CA;D.D. Blankenship, D.A. Young, be restarted from thedepth 3559 m(about Institute for Geophysics, University Of Texas 150 m towards ice-waterboundary) in the new Austin, Austin, TX; W.H. Lipscomb, S.F. Price, , borehole called 5G-2 (previously in the Los Alamos National Laboratory, Los Alamos, 2008/2009 seasonwithin the 5G-1 borehole NM; J.V. Johnson,,University of Montana, the drill stack was lost as a consequence of Missoula, MT borehole inclination).The 2009/2010 season will be devoted to developing the deep the

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Program Book Final.pdf 13 3/3/2010 11:13:15 AM With therecent multiyearacquisition of 2007 National Research Council report satellite laser altimetry, it is now possibleto (Exploration of Antarctic Subglacial Aquatic observe the movement of subglacial water Environments: Environmental and Scientific through entire basins. The last four decades of Stewardship) and the Scientific Committee on airborne radar sounding campaigns have Antarctic Research 2009 Code of Conductfor brought unprecedented resolution of ice the Exploration and Research of Subglacial thickness, icestructure andbasal properties Aquatic Environments recommend that the for nearly the entire Siple Coast drainage. numbers of microbial cells contained in or on Within the last decade several models have the volume of any material or instruments been developed and implemented to explain added to or placed in these environments both theproduction andtransport largescale should not exceed that presentin an transport of water beneath the Antarctic ice equivalent volume of deep ice. We intend to sheet.Recentadvances to theclassical conform to these recommendations and plan to jökulhlaup theory have been developed to rigorously test the technology prior to any explain the timing, magnitude, and evolution of attempt at subglacial access. To penetrate the episodic subglacial waterflow.Verification of 700-800mof overlyingice,ahot waterdrilling both the long term transport and flood system has been designed which will have evolution models has been limited to mass approximately 80 L minflow capacity and be budgets for entire basins or focused on capable of drillingand maintaining holesofup individual events.Using an thermomechanical to 25 cm in diameterfor 8 days.Integrated icesheet model to provideengalcial within the drilling system are large-scale water temperatures distribution andbasal melt rate, purification, filtering, ultraviolet radiation, and RES data on icethickness and basal reflections heat sterilizationmodules,which will remove we develop self consistent method for dissolved organic carbon (DOC) species and modeling basal waterdistribution and imaging sterilizethe effluent.The volume of liquid basal water systems. This model is then watergenerated whendrilling each borehole tested in several locationsthroughout theSiple will be at least 41 mthe residence time of Coast where subglacial lakes areknown to water through the system is approximately 8.5 clusterand forwhich a hydraulic linkage has hours, and after8days of borehole operations, been demonstrated. Even the older RES data the borehole fluid should be completely proves highly useful for linking individual lakes. circulated through the system at least 20 times The satellite altimetry often reveals lakes (~920 m³). These previously undetected, but still visiblein the specifications, togetherwith the estimated RES data. In summary close couplingof the concentration of cells and DOC in theice and multiple lines of geophysical data with an ice from contamination, were used to determine sheet model hasthe potential to reveal a WISSARD clean system requirements. To unprecedented level of detail about the continuously purge contaminants during 8 days subglacial water system and its affect on the of borehole operations, ourclean access flow of theoverlying ice. drilling system requires the capacity to remove at least 9 x10 cells and 5 kg of DOCfromthe Biologically andChemically Clean drilling fluid. http://brent.xner.net/ Subglacial Access Drilling Subglacial Life and the Search forLife Christner, Brent Christner Brent Craig; Priscu Beyond Earth John C; Mikucki Jill; GerasimoffMichael; Bolsey Robin; Lebar Done; Bentley Charles R Cockell, Charles Cockell Charles; McKay B.C. Christner, , Louisiana State University, Christopher P; Voytek Mary A; Doran PeterT; Baton Rouge, LA; J.C. Priscu,,Montana State Siegert Martin John; Pearce David; Tranter University, Bozeman,MT; J. Mikucki, , Martyn; Wadham Jemma L; Bagshaw Dartmouth College, Hanover, NH; M. ElizabethAC. Cockell, ,Open University, Gerasimoff , R. Bolsey , D. Lebar, C.R. Bentley, Milton Keynes, UNITED KINGDOM; M. Tranter, , University of Wisconsin, Madison, WI J.L. Wadham, E.A. Bagshaw, , University of Bristol, Bristol, UNITED KINGDOM; M.A. Environmental stewardship is aforemost Voytek,, NASA Headquarters, Washington DC, priority during the exploration of pristine WA;D. Pearce,, BritishAntarctic Survey, Antarctic subglacial environments. The Cambridge, UNITED KINGDOM; C.P. McKay,, WISSARD (Whillans Ice Stream Subglacial NASA Ames Research Centre, Moffett Field, Access Research Drilling) project will CA; P.T. Doran,, University of Illinois, Chicago, implement thebiologically andchemically IL; M.J. Siegert, ,University of Edinburgh, cleanest technologies practicable during all Edinburgh, UNITED KINGDOM phases of drilling and subglacial access. A

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Program Book Final.pdf 14 3/3/2010 11:13:15 AM Theassessment of the habitability of other and the estimated geothermal heat flux is planetary bodies is necessarily constrained by threetimes theassumedcontinental what we knowabout life on the Earth. background. The estimated volume of Increasingly, the community has recognised produced melt wateris discussed. We show that some of the most promising sites for that the enhanced geothermal heat flux prebiotic chemistry or extant life beyond Earth required for melting coincides with a granitic are subglacial environments.These body, and contend that the elevated heat is environments include: the ocean of the Jovian causedbyradiogenics ratherthanvolcanism. moon,Europa, andpossiblyCallisto; bodies of The subglacial lake-district and underlying liquid water within the Saturnian moons, granitic body marks the inland boundary of the Enceladus and Titan; and subglacial Cook Ice Streams; a body of ice with an environments on Mars. Subglacial established retreat signature. Between the environments on theEarthare likelyto differ upstream lake-district and the ice-shelf from theseenvironments in some important terminus lies a hitherto undiscovered respects, such as the presence of subglacial basin. There is widespreadevidence allochthonous organic carbon in terrestrial ices of waterwithin thedeepbasin. Mechanisms produced by the photosynthetic biosphere. by which the lubricated bed of the ice stream However, the diversity of anaerobicredox could affect ice-sheet dynamics in the area are couplesusing elements derived from the discussed. Although the water depth of the lithosphere and gases produced in situ provide lake is unknown the high melt-rate of the important insights into the thermodynamicand overlying ice column suggests a short kinetic constrains to life in extraterrestrial residency time. Thelakeisidentifiedasa subglacial environments. Furthermore,the target to drill through and recover a sediment contamination control procedures and core that could potentially reveal the Pliocene exploration technologiesusedto explore history of EAIS. terrestrial subglacial environments yield new procedures and ideas for the sampling and DrainageofSubglacial Water Systems analysis of extraterrestrial subglacial Beneath Ice Sheets environments. Creyts, Timothy Creyts Timothy T; Schoof Subglacial Lake-districtReveals East ChristianT.T. Creyts, Lamont-Doherty Earth Antarctic Heat Flux Anomaly Observatory, Columbia University,New York, NY; C. Schoof, Earth and Ocean Sciences, Corr, Hugh Corr Hugh;Hindmarsh Richard C Univ. British Columbia, Vancouver, British A; Ferraccioli Fausto; Armadillo Egidio; Columbia, CANADA Jordan Tom AH. Corr, R.C. Hindmarsh, F. Ferraccioli, T.A. Jordan,, British Antarctic Dynamic lakes that cause ice surface elevation Survey,Cambridge, UNITED KINGDOM; E. change require ample generation and supplyof Armadillo, Dipartimento per lo Studio del water from upstream sources. The hydraulic Territorio e delle Sue Risorse, Universita’ di system delivers watertothese lakeseither Genova, Genova, ITALY through a distributed or channelized morphology. In this paper, we investigate the Unlike the West Antarctic ice sheet, which lies effects of subglacial water drainage resulting over a crustal rift that has volcanism on its from spatially distributedwater sheets. In our flanks and associated elevated geothermal model, the weight of overlying ice is supported heat flux, the East Antarctic ice sheet (EAIS) by both water pressure and various sizes of lies on generally aseismic continental crust that bed protrusions that penetrate the water exhibits little volcanic activity. The majority of sheet. Each of the various sizes bears a subglacial lakesfound in EAIS are believed to different magnitude of theoverlying ice based be formed because at a‘normal’ background on a linearstress recursion that balances geothermal heat flux of ~50 mW m-2, the ice forces at the bed. Previous results have shown is sufficiently thick to be at the pressure that water depth can be a multi-valued melting point. Here we identify from ice function of both effectivepressure (ice soundingradar data from East Antarctica a overburden minus water pressure) that drives cluster of six subglacial lakes, within a circular sheet closureand hydraulic gradient that area of radius 70 km.One of thelakes,which drives waterflow (Creytsand Schoof,2009). sits astride an ice-divide, has a clear down Curvature andstructure of this multi-valued warping of internal layers. A forward model is water depth function depend on the protrusion used to match the layertrajectory and shows size distribution.Switchesbetween different that thesubglacial melt rate to be very much branches of the water depth relationship greaterthantypical values forEastAntarctica correspond to either the establishment or shut-

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Program Book Final.pdf 15 3/3/2010 11:13:15 AM down of a ‘connected’ (or efficient) drainage roughly since theonset of the decrease in the system. We build upon and extend previous extent of the ice shelves in the region, or (b) a work to show how along-path discharge affects relatively steady,less extraordinary water depth and switches from one stateto sedimentation rate within the quiet another. We conclude by relating state environment of the sub-glacial lake. This behavior to subglacial conditions where second interpretation may be supported by the dynamic lakes are found. high penetration shown by the sub-bottom acoustic profiles,downto thereflector at the Sub-glacial Lake Environment and Facies base of the 40-mthick layered fill. This Revealed by Larsen B Ice Shelf observation suggests the presence of a Disintegration relatively fine grain-size,without appreciable variations. In fact, episodes of coarse grain Domack, Eugene DomackEugene W; Leventer size and/or acoustic fancies changes would be Amy; Rebesco Michele; Zgur Fabrizio; expected in case majorenvironmental Brachfeld Stefanie A; Willmott Veronica; changes.If we assume that the LGM was the HalversonGalen P; Lavoie CarolineE.W. last time the ice was grounded within the fjord, Domack, V. Willmott, C. Lavoie, Geoscience, the average sedimentation rate of the layered Hamilton College, Clinton, NY; A. Leventer, fill would be of the order of fewhundred Geology, ColgateUniversity, Hamilton ,NY; M. cm/kyr a rate comparableto that of the Palmer Rebesco, F. Zgur, Geofisica, Istituto Nazionale Deep record on the opposite side of the di Oceanografia edi Geofisica Sperimentale Antarctic Peninsula. What is uniquehere is that (OGS), Sgnonico, ITALY; S.A. Brachfeld, this record would have been deposited in a Department of Geology,Montclair State sub-glacial lake environment, sincethe ice University,Montclair,NJ; G.P. Halverson, cover is known to have persisted in the area Geology & Geophysics, The University of forthe entire Holocene. Moreover,this Adelaide,Adelaide, SouthAustralia, extraordinary record would have also recorded AUSTRALIA the abrupt transition to an open sea setting, with acceleratedice discharge following the The identification of subglacial lake sediments break-up of the ice shelf. This sedimentary in ancient sequences is difficult to infer record, and other similar, yet unsampled because subglacial lakesare themost sedimentary sequences, provide awindow inaccessibledeposystems for direct study of throughwhich to decipherthe dynamics of the process/product. To date the best available sub-ice processes that result in and accompany analogs are recent deep basins previously theloss of icemass andits transfer to oceanic covered by the Larsen Ice Shelfsystem. The systems. collapse of the Larsen-B Ice Shelf (LIS-B) and subsequentrapid retreatof the Crane Glacier Environmental Protection and resulted in the formation of 15 km long fjord. Stewardship of Subglacial Aquatic The fjord trough is characterized by the Environments presence of three deep (>1000 m) and narrow (~1 km wide) basins. The basins are Doran, Peter Doran PeterT; VincentWarwick separated by more elevated thresholds whose FP.T. Doran, Earth and Environmental morphology of elongated ridges and gutters Sciences, University of Illinois at Chicago, sub-parallel to theaxisofthe fjord, is Chicago, IL; W.F. Vincent, Centre for Northern interpreted as sub-glacial bed forms that Studies (CEN) & Dept de Biologie, Laval formed as the result of deposition of subglacial University, Quebec, Quebec, CANADA till--beneath grounded ice. At the time of ice grounding, thebasins existed as sub-glacial Antarctic subglacial aquatic environments have lakes. More than 40 m of horizontally stratified been documented for some time using remote sedimentsare presentwithinthe deepestof sensing(geophysical) techniques,but only the fjord basins.A kasten core of the very recently have there been plans devised uppermost 2.6 meters of sediment documents and implemented to enter and study these that recent sedimentswere deposited at ahigh environments directly. The long lead up to the rate (2 m/year) under open marine conditions sampling of theselakes is largely related to the following ice shelf retreat. The underlying logistical difficulty of doingso, but also dueto sediments likely were deposited in a sub- the cautious approach warranted by the glacial lake setting; thesesediments will be pristinenatureofthe environments,and their jumbo piston cored during cruise NBP10-01, almost completely unknown capacity to sustain during January-February 2010. Our working viable ecosystems. It is because of the need hypotheses are that thesesediments were for caution that the U.S. National Science deposited (a) over the past ~ 30 years, Foundation requested guidance from the

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Program Book Final.pdf 16 3/3/2010 11:13:15 AM National Academies to address standards of NH; D.M. Holland, , New York State University, responsibleexploration of subglacial aquatic New York, NY environments. In response, the National Research Council of theNational Academies WISSARD is a 6-year NSF-funded project created the Committee on the Principles of which involves 13 PIs at 9 institutionsthat will Environmental andScientific Stewardship for use an interdisciplinary science approach to theExplorationand StudyofSubglacial study the subglacial environment of the Environments.The committee made13 Whillans Ice Stream in West Antarctica. It is recommendations towards this end. The NRC split into three sub-projects: LISSARD (Lake study and recommendations will be reviewed in andIce Stream Subglacial Access Research this talk as well as an assessment of the Drilling);RAGES (Robotic Access to Grounding- study’s impact, including ongoing international zones for Exploration andScience); and GBASE development of a Code of Conduct to explore (GeomicroBiology of Antarctic Subglacial andprotect Antarctic subglacial waters. Environments). LISSARDfocuses on investigating the role of active subglacial lakes Evidence for Microbial Metabolism at - in controllingtemporal variability of ice stream 15°C in an Antarctic Subglacial dynamics andmass balance. RAGES Environment concentrates on stability of ice stream grounding zones which may be perturbed by Doyle, Shawn Doyle ShawnM; Achberger increasedthermal ocean forcing, Amanda M; Montross Scott N; Brox Timothy; filling/draining cycles of subglacial lakes, Suematsu Kohei; Skidmore Mark L; Christner and/or internal ice stream dynamics. GBASE Brent CraigS.M. Doyle, A.M. Achberger, B.C. addresses metabolic and phylogenetic Christner, Biological Sciences, Louisiana State diversity, and associated biogeochemical University, Baton Rouge, LA; S.N. Montross, T. transformations in subglacial lake and Brox, M.L. Skidmore, Earth Sciences, Montana grounding zone environments. These sub- State University, Bozeman, MT; K. Suematsu, projects are connected scientifically through TheInstitute of LowTemperature Science, commoninterest in coupledfluxesofice, Hokkaido University, Sapporo, JAPAN; subglacial sediments, nutrients andwater,as Analysis of the gases entrapped in sediment- well as by the common need to characterize rich basal icefromthe Taylor Glacier,an and quantify physical, chemical andbiological outflow glacier of the East Antarctic Ice Sheet, processes operating subglacially. The project have revealed anomalies with respect to the will focus on the lower Whillans Ice Stream, concentrations of CO2 and CH4 (>1000 times where three hydrologically connected atmospheric) and O2 (<1 subglacial environments that lie within close geographical proximity can be accessed: a TheWhillans IceStreamSubglacial subglacial lake (Lake Whillans); wet subglacial Access Research Drilling(WISSARD) sedimentsincluding the grounding-zone Project: an Integrated Studyof Marine Ice wedge; and the sub-ice-shelf cavity. Direct Sheet Stability and Subglacial Life samplingwill yieldseminal informationonthe Habitats in West Antarctica glaciological, geological and microbial dynamics of these environments and test the Fricker, Helen FrickerHelen Amanda; Tulaczyk overarching hypothesis that active hydrological Slawek M; Powell Ross D; Priscu John C; systems connect various subglacial Anandakrishnan Sridhar; Christner Brent environments and exert major control on ice Craig; Fisher Andrew T; Holland David M; sheet dynamics, geochemistry, metabolic and Jacobel Robert W; Mikucki Jill; Mitchell phylogenetic diversity,and biogeochemical Andrew Charles; Scherer Reed P; transformations of major nutrients within Severinghaus Jeff H.A. Fricker, J.P. glacial environments.Wewill present an Severinghaus, IGPP, Scripps Institution of overview of the hypotheses, time-line, Oceanography, La Jolla, CA; S.M. Tulaczyk, significance as well as the challenges that we A.T. Fisher,, University of California, Santa foresee.http://www.wissard.org Cruz, Santa Cruz, CA; R.D. Powell, R.P. Scherer, , Northern Illinois University, DeKalb, Synthesising Multiple Remote Sensing IL;S.Anandakrishnan, ,PennsylvaniaState Techniques for Analysing Subglacial University, State College, PA; R.W. Jacobel,, Hydrologic Systems: Application on St.OlafCollege, Northfield,MN; J.C. Priscu, MacAyeal Ice Stream, West Antarctica A.C. Mitchell, , MontanaState, Bozeman, MT; B.C. Christner,, Louisiana State, Baton Rouge, Fricker, Helen Fricker Helen Amanda; LA;J.Mikucki,,DartmouthCollege, Hanover, Scambos Theodore A; Carter Sasha P; Davis Curt H; Haran TerenceM; Joughin Ian R;

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Program Book Final.pdf 17 3/3/2010 11:13:15 AM MacAyeal Douglas Reed H.A. Fricker, S.P. WISSARD is an ambitious sub-glacial Carter,IGPP, Scripps Institution of exploration program encompassing the Oceanography, La Jolla,CA; T.A. Scambos, disparate needs of the LISSARD, GBASE, and T.M. Haran,, National Snow andIce Data RAGESprojects. Accessing thesub-glacial Center,Boulder,CO; I.R. Joughin, ,University environmentrequires hot-water-drilledbores of Washington,Seattle, WA;C.H. Davis, , ranging from a about 15 to 50 cm diameter, University of Missouri-Columbia, Columbia, dependenton science requirements, MO; D.R. MacAyeal,, University of Chicago, anticipated occupation period, and resulting Chicago, IL allowance for freeze-back.Calculations indicate 1 to 3 megawatts is required for We present an analysis of theactivehydrologic drilling and related processes. LISSARD and system of MacAyeal IceStream(MacIS),West GBASEprojectsrequiresmallerbores and Antarcticafromasynthesisofmultiple remote lower heat flux, but environmental stewardship sensingtechniques: satellitelaser andradar and the scientific objectives impose challenging altimetry; satellite image differencing; and aseptic requirements. The RAGES project hydrostatic hydropotential mapping (using a deploysasubmarine ROVvia the largest satellite-derived digital elevation model (DEM) bores, requiring the largestheatflux. and abedrockDEM from airborne-radio echo Maintainingthe bore forperiods that might sounding). Combining these techniques exceed 300 hoursbyrecirculating salt- augments the information provided by each contaminated water presents engineering and one individually, and allows us to develop a operational challenges.We presentour protocol for studying subglacial hydrologic current design embodiment encompassing systems in a holistic manner. Our study drilling, filtration and related systems reveals five large active subglacial lakes under addressing critical engineering, environmental MacIS, thelargest of which undergoes volume stewardship,scientific deployment andother changes of at least 1.0 km3. We discuss the issues. www.wissard.org hydrologic propertiesofthissystemand present evidence for links between the lakes. Exploring FormerSubglacial Hodgson At least three of the lakes are co-located with Lake, Antarctica: Geomorphology, sticky spots. We also find evidence for surface Limnology and Paleolimnology elevation changes due to ice dynamic effects (not just water movement) caused by changes Hodgson, Dominic Hodgson Dominic; Roberts in basal resistance. We show that satellite Steve; Bentley Michael; Smith James; radar altimetryis of limited use for monitoring Verleyen Elie; Vyverman Wim; Leng Melanie; lake activity on fast-flowing ice streams with Sanderson David; Johnson Joanne; Hodson surfaces that undulateon ~10 km) length Andy D. Hodgson, S. Roberts, J. Smith, J. scales.Finally,toassess whether thereis a Johnson,,BritishAntarctic Survey,Cambridge, link between lake flooding and ice dynamics, UNITED KINGDOM; M. Bentley, Dept. we examined the largest lake for flow speed Geography, University of Durham, Durham, changes during fill and drain cycles with UNITED KINGDOM; E. Verleyen, W. Vyverman, several ASTER images. Ice velocity mapping Dept.Biology,University of Ghent, Ghent, using ASTER image pairsspanning periods BELGIUM; M. Leng, Isotope Geoscience Lab, when the lake is drained show flow speeds up NERC , Keyworth,UNITED KINGDOM; D. to 40 m/yr slower than when the lake is filled. Sanderson, , SUERC, East Kilbride, UNITED We infer that flow speed decreased as a result KINGDOM; A. Hodson, Dept. Geography, of increased basal resistance (from zero to University of Sheffield, Sheffield, UNITED non-zero as the ice encountered the basal KINGDOM sediments). Thescaleofthe slowdown is similarto modeled results on nearby ice Direct exploration of subglacial lakes buried streams. deep under the Antarctic Ice Sheet has yetto be achieved. However, at retreating marginsof UW-Wisconsin (ICDS) WISSARD Drilling the ice sheet, there are a number of locations Program: Environmental Stewardship, where formersubglacial lakesare emerging Engineering, andScientific Objectives from under the ice but remain perennially ice covered. We present a study of Hodgson Lake Gerasimoff, Michael Gerasimoff MichaelM. (72° 00.549’S, 068° 27.708’ W), including its Gerasimoff, Space Science and Engineering geomorphology, limnology and Center, University of Wisconsin, Madison, palaeolimnology. Thickperennial icecover Madison , WI persistsoverthe lake todayand the waters have remained isolated from the atmosphere. Nutrient concentrations within the ranges of

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Program Book Final.pdf 18 3/3/2010 11:13:15 AM those found in the accreted lake ice of Lake As an example, the algorithm was employed to Vostok. TOC and DOC are present, but at lower twoseriesofaverage values of δ18O and of concentrationsthanincontinental rain.No δ15N in trapped gasesofthe Vostok ice core organisms were detected using light (http://nsidc.org/data/nsidc-0107.html). The microscopy.Increases in SO4and cation primary results in contourpatterns (Fig. 1) concentrations at depth and declines in O2 feature generally that the δ18O (Fig.1a)have provide some evidence for sulphide oxidation 21 significantchange-points,which is more and very minorbacterialdemand upon O2. frequentthan that in theδ15N with 15 change- However, in general thechemical markersof points (Fig.1b), the coherency (Fig.1c) life in the water are inconclusive. The between Fig.1a and b appears mainlypositive palaeolimnology of the lake was studied using before 142.7 Ky BP while negative afterthen a3.8 msedimentcore dated using a on longer time-scales.Key references: Jiang, combination of radiocarbon, OSL, and relative J., X. Gu, and J. Ju, “Significant changes in palaeomagnetic intensity dating. Four subseries means and variances in an 8000- stratigraphic zones (A–D) were identified. year precipitation reconstruction from tree Zones A–C were deposited between Marine rings in the southwestern USA”, Ann. Isotope Stages 5–2 and zone A during Stage 1. Geophys., 2007, 25: p1519–1530, www.ann- The palaeolimnological record tracks changes geophys.net/25/1519/2007/ Jiang, J.: in the subglacial depositional environment “Scanning detections of multi-scale significant linkedprincipally to changing glacier dynamics change-points in subseries means, variances, and mass transport andindirectly to climate trends and correlations”, in < 2009 Sixth change. There is no evidence of overriding International Conference on Fuzzy Systems glaciersbeing in contact with thebed and Knowledge Discovery>, V5:609-613, IEEE reworkingthe stratigraphy or removing this Press. sediment. This suggests that the lake existed in a subglacial cavity beneath overriding LGM Low-frequency Radar Profiles of the ice. In zone D there is a transition to finer Recovery Lakes grainedsediments characteristic of lower energy delivery coupled with a minor increase Kohler, Jack LangleyKirsty; Kohler JackK. in the organic content. Evidence of biological Langley, J. Kohler,, NorwegianPolar Institute, activity is sparse. TOC varies from 0.2 to 0.6 Tromso, NORWAY

Scanning Detection of Multiscale Four new large sub-glacial lakes (SGLs) were Significant Trend-Changes in Ice-core identified recently at the head of the Recovery Records Glacier ice stream in East Antarctica, using MODIS imagery and ICESat elevation data. The Jiang, Jianmin Jiang Jianmin; Gu Xiangqian J. surface areas of these lakes would make them Jiang, ,Training Centre of China among the largest SGLs in Antarctica, second Meteorological Administration,Beijing,Beijing, only to Lake Vostok.Beyondtheir size,the CHINA; X. Gu,, Chinese Academy of Recovery Lakes (RL) are compellinglylocated Meteorological Sciences, Beijing, Beijing, just at the onset of fast flow in the Recovery CHINA Ice Stream, suggesting a linkage between the presence of water at the bed and the initiation Abstract The author has developed four of rapid ice flow In January 2009, the scanning algorithms for detecting coherency of Norwegian-US IPY traverse passed over the RL multiscale significant changes in subseries area, en routefromSouth Pole to Norway’s means, variances and trends between two time Troll Station (Fig.1). Here we present low series and the subseries correlation changes frequency radar data collected over the RLs respectively (Jiang, 2009).Here we present during the traverse,and examine the evidence oneofthe four,the scanning F-test for fortheir existence basedonthe reflectivity of detecting multiscale change-points in subseies thebasal reflectorand on therelativeflatness trends (regressionsto time),specially for of the basal interface. drilling cores which are recorded in unequal intervals. Scanning detectionsof changes in PotentialProxies Held In Sediment subseries means andvariances in sediment Inclusions From IceCores Of The Vostok cores were demonstrated by Jiang et Station Borehole al.(2007). These algorithms feature grafting the wavelet technique onto the classical Leitchenkov, German Leitchenkov German L; statistic test andgivingstatistic criteria at a Belyatsky Boris; Bulat Sergey;Lipenkov confidence level, as well as automatic and Vladimir G.L. Leitchenkov, B. Belyatsky, objectivedetection on varioustimescales. Antarctic Geoscience, Institute for Geology and

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Program Book Final.pdf 19 3/3/2010 11:13:15 AM Mineral Resources of the World Ocean, St.- andnext step of studywill includeadditional Petersburg, RUSSIAN FEDERATION; S. Bulat,, SHRIMP analysis to define ages of this U- Petersburg Nuclear Physics Institute, St.- bearing minerals. The compositions of the rock Petersburg, RUSSIAN FEDERATION; V. clasts suggest that the bedrock situated to the Lipenkov, ,Arctic andAntarctic Research west of Lake Vostok is sedimentary. The age Institute, St.-Petersburg, RUSSIAN data on the detrital accessory minerals FEDERATION (studiedso farintwo inclusions) allowusto speculate that the provenance of these The borehole at the Vostok Stationhas been sedimentary rocks −the Gamburtsev drilled into an accretedice layer originating Mountains and Vostok Subglacial Highlands, is from refreezing of the lake water. This layer mainlyrepresented by Paleoproterozoic and contains random sediment inclusions, nine of Mesoproterozoic-Neoproterozoic crustal which have been studied using state-of the-art provinces. analytical techniques.Six inclusionscomprise soft aggregates mainly consisting of clay-mica Modeling the Spatial Variation Of Englacial minerals and micron-sized quartz grains while Radar Attenuation: Application To The three others contains quite large rock clasts. Vostok Flowline And Implications For The Electron microscopy of soft inclusions extracted Detection Of Subglacial Lakes from depth of 3559 mhave revealed small (several micron-sized) particles of sulfide MacGregor, Joseph MacGregor Joseph A; minerals (molybdenite, sphalerite and pyrite). Matsuoka Kenichi; Winebrenner Dale P; Two principal ways of theirorigincould be Waddington Edwin D; Pattyn FrankJ.A. suggested: i) disintegration of ancient MacGregor, Institute for Geophysics, metamorphic rocks by glacial erosion and University of Texas, Austin,TX; K. Matsuoka,, deposition over the western lake shore NorwegianPolarInstitute,Tromso, NORWAY; (exaration)and ii) recent endogenous K. Matsuoka, D.P. Winebrenner, E.D. processes in a depth. Pyrite shows typical Waddington, Dept. of Earth and Space cubic-shaped crystalline morphology which is Sciences, University of Washington, Seattle, unlikely to be preserved in the course of ice WA; D.P. Winebrenner, Polar Science Center, exaration as this mineral is quitesoft. University of Washington, Seattle, WA; F. Moreover, under highly oxidative conditions Pattyn, Dept.des Sciences de la Terre et de expected in the lake due to oxygen l'Environnement, Universite Librede Bruxelles, accumulation upon ice melting pyrite particles Brussels, BELGIUM should not be resistant but rather replaced by iron oxide followed by iron oxihydroxide as a Knowledge of the spatial variation of englacial final product. Molybdenite and sphalerite were radar-attenuation rates is poor, but it is detected in the assemblage with pyrite and needed to accurately infer englacial and basal provide an extra support for in situ formation propertiesfrom ice-penetrating radar data, of mineral assemblages by recent endogenous including the locationof subglacial lakes. activity pointing out theirrapid trap in Attenuation rates depend on the spatial accretion ice. Such endogenous activity in a variation of temperatureand soluble impurity depth provides evidence for hydrothermal concentrations. Because temperatureand activity in theLakeVostok (additionally to impurity concentrations are measured only at some other arguments). Rock clasts from two the surface or in boreholes or ice cores, models inclusions (3582and 3607 m) consists of of their spatial variation are required to predict poorly-rounded quartz and minor amounts of attenuation rates in ice sheets. Here we accessory minerals andis classified as evaluate several models of thespatial variation quartzose siltstone.21grainsofzirconand 5 of attenuation rates andpresent an example of grains of monazites (from 2-5 to 30-40 μm in their application along aflowline that crosses size) have been identified in the siltstone and over Lake Vostok, East Antarctica, and through dated by SIMS SHRIMP-II. Twoage clusters the Vostok ice core. The first and simplest have been recognized forthese detritalgrains, possiblemodel is auniform, depth-averaged in the ranges 0.8−1.2 Ga and 1.6−1.8 Ga.The attenuation rate everywhere along the largest inclusion (3608 m) contains 13 poorly- flowline; thenext simplest model uses spatially rounded rock clasts (ranging in size from 0.5 varyingtemperatures from a to 3.5 mm) which were identified as thermomechanical ice-sheet model,but sandstones and siltstones. Most of clasts is assumes uniform impurity concentrations. dominatedbyquartz; oneclast consists Subsequent models also use radar-layer completely of apatite; and two clasts have depthsand/orvelocities from theice-sheet considerable quantity of feldspar.11zircons model to extend Vostok impurity-concentration and 11 monaziteswere detected in these rocks data alongthe flowline andpredict their spatial

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Program Book Final.pdf 20 3/3/2010 11:13:16 AM variation. We find that models that include most probably passed throughover-deepened spatially varying temperatures predict large troughs (not yet fully developed at the time of differences in roundtrip attenuation (> 10 dB) the Miocene floods) that today lie beneath comparedtothe modelthatassumes a modernoutlet glaciers. One unknown is the uniform attenuation rate; these differences are fate of sediment eroded by these subglacial large enough to confound subglacial lake floods; sedimentary deposits, if they existed, detection.Modelsthat includethe spatial have not been identified in exposed areas of variation of impurity concentrations introduce the continent. Onepossibility is that much of smaller (< 5 dB) changes to the roundtrip the debris may ultimately have frozen onto the attenuation.Thisworkshows that an basal ice and was carried out to the continental attenuation-rate model tied to an ice-core site shelf. A second unknown is the ecological and can be satisfactorily extended spatially using climateimpact of largevolumesoffreshwater radar-layer depths and atemperature model. discharging into theRossEmbayment, Theapplication of such models to ice- particularly during the mid-Miocene when penetrating radar datasets will permit more ablation (via melting) of the ice surface may reliable detection of subglacial lakes, have preconditioned the Southern Ocean to particularly in regions with large ice-thickness abrupt change. changes. DetectingWet Ice-sheet Beds Across The Geomorphic Signature Of Subglacial Antarctica UsingRadar:AFeasibility Floods AssessmentUsing Three-dimensional TemperatureAnd RadarAttenuation Marchant, David Marchant DavidR; Sugden Models DavidD.R. Marchant, Earth Sciences, Boston University,Boston,MA; D. Sugden,School of Matsuoka, Kenichi Matsuoka Kenichi; Pattyn GeoSciences, The University of Edinburgh, Frank; MacGregor Joseph AK.Matsuoka, Edinburgh, Scotland,UNITEDKINGDOM Earth and Space Sciences, University of Washington,Seattle,WA; K. Matsuoka,, There is geomorphicevidence in the NorwegianPolarInstitute,Tromso, Troms, Transantarctic Mountains supportingthe idea NORWAY; F. Pattyn, ,Université Libre de of catastrophic drainage of,and erosion from, Bruxelles, Brussels, BELGIUM; J.A. MacGregor, subglacial lakes in East Antarctica; the University of Texas at Austin, Austin, TX erosionalfeatures includevast tracts of scoured-bedrock terrain, bedrock-channel Diagnosing subglacial conditions using systems, and scabland topography. Some of observed radar power returned from the bed themeltwater tractsextendfor over 50 km in (bed-echo intensities)requiresacorrectionfor length, and may be linked to extensive the dielectric attenuation through the ice offshore channels.Our aimistouse overburden.Thisattenuation depends on ice geomorphology to help understand the temperature and chemistry, so it is spatially dynamics of subglacial meltwater flow andits varying. The difference between the specular role in glacial erosionand deposition.The reflectivities of wet and dry beds is up to 25 bedforms in the Dry Valleys area give an dB.A depth-averaged attenuation-rate insight into the locations, magnitude, and difference of ~4 dB/km(one way) in 3-km- frequency of subglacial outbursts in a large thick ice can therefore easily confound areathatwas formerlythe bed of an expanded interpretations of subglacial conditions. A East Antarctic ice sheet. Our mapping results recent estimate of thespatial variation of show that the subglacial channels are attenuation rates in central West Antarctica anastomosing, with potholes at junctionsand shows that they vary by up to 5 dB/kmwithin reverse gradients in longitudinal profiles. a ~120-km by ~120-km area. These Flood magnitudes are inferred to be on the observations motivateareassessmentofthe order of the Lake Missoula floods (e.g., huge conventional belief that brighter anddimmer discharges associated with recession of the beds can be simply interpreted as wetter and Laurentideice sheet).Modelingstudies point drierbeds,respectively. We estimated the to asourcefor meltwater in interiorEast three-dimensional attenuation-rate fieldfor the Antarctica, with the possibility that significant entireAntarctic icesheet usinganexisting water bodies were temporarily held in place by temperature-dependent attenuation-rate a transient ice dam (cold-based ice) on the modeland temperatures from a inland flanks of the Transantarctic Mountains. thermomechanical model. Forthese initial The latest flood to cross the Dry Valleys region calculations, we ignore spatial variationsin likely datesto middle Miocene time. Younger chemistry, sincepreviousattenuation-rate floods may have occurred, but the meltwater estimates at ice-core sites showed that ice

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Program Book Final.pdf 21 3/3/2010 11:13:16 AM chemistry is of secondary importance. To determine theinteraction level of the lake. For mitigate uncertainties relatedto the poorly example,lakes at theheadoffast flowingice known spatial variation in geothermal flux we streams couldplayamuch stronger role in evaluated the robustness of our results using terms of ice-sheet dynamics than lakes in several geothermal-flux models that were inner-continental basins.Also icethickness calibrated using borehole-temperature profiles playsanimportant role in thehydrodynamic and the locations of known subglacial lakes and regime of subglacial lakes. Thegeneration of ice streams,where the bed is presumed to be different lake categories, in relation to their wet. Bed reflectivity is assigned based on the specific settings, allowsus to describethe temperature model and the bed-returned overall physical conditions and the potential power is predicted. We discuss properties of interaction level of subglacial lakes with their depth-averaged attenuation across Antarctica environment. and potential pitfalls related to the diagnosisof subglacial conditions using radar. Blood Falls, Antarctica: Insights Into Subglacial Microbial Energetics Subglacial Lake Regimes For Different Lake Categories Mikucki, Jill Mikucki Jill; Priscu John CJ. Mikucki, Earth Sciences and Environmental Mayer, Christoph Mayer Christoph; Thoma Studies, DartmouthCollege,Hanover,NH; J.C. Malte; Grosfeld Klaus; Siegert Martin John C. Priscu, Land Resources and Environmental Mayer, M. Thoma, Commission for Glaciology, Sciences,Montana State University, Bozeman, Bavarian Academy of Sciences andHumanities, MT Munich, GERMANY; M. Thoma, K. Grosfeld, Climate Sciences, Alfred Wegener Institute for Thesubglacial environment is oneofthe most Polar and Marine Research,Bremerhaven, difficult portions of the cryosphere to access GERMANY; M.J. Siegert, School of andonlyrecently,incollaboration with large- GeoSciences, University of Edinburgh, scale drilling projects, are ecologists beginning Edinburgh, UNITED KINGDOM to explore themoreremote reaches of the subglacial biome. Thesubglacial environment Since the first discovery of subglacial lakesin beneath the Taylor Glacier, a cold-based polar the late 1960s the knowledge about subglacial glacier in the McMurdo Dry Valleys, Antarctica water bodies has changed dramatically. First supports a metabolically and genetically only a small number of lakes (17) were diverse biosphere that can be used as amodel identifiedinthe centre of theAntarctic Ice for other subglacial systems. The Taylor Sheet, including Lake Vostok. The development Glacier’s subglacial discharge, Blood Falls, is a of ideas concerning internal hydrological brine remnantfromPliocene marine waters conditions and mass exchange with the ice that is inhabited by cryo-and halotolerant sheet took a longtimeto develop. Since the organisms that are related to marine species. mid 1990s about 280 subglacial lakes have Surfacemeltwater does not penetrateto the been discovered underneaththe ice sheet, base of the Taylor Glacier and no oxygen is ranging from some kilometres to about 250 km detectedinoutflow waters suggesting that in dimension, being covered by an ice layer anoxia is an important regulator of microbial from less than 2 km up to more than 4 km energetics. Limited organiccarbon supplyfrom thick. The lakes are located at several theabsence of contemporary photosynthesis characteristic locations across Antarctica. Also appears to have influenced the choice of the interaction between lakes and the metabolic pathways employed by this surroundingice sheet is highly variable ranging subglacial community.Moleculardata and from likelyclosed systemswith very little mass biogeochemical measurements indicate that exchange to waterbodieswith extensive, rapid chemoautotrophicactivity is present and and possibly periodical water discharges. Here suggests that subglacial systems can be we provide a comprehensive summary of the sustained independent of allochthonous fixed principal conditionsregardingthe internal carboninputs. Isotopic measurementsofiron, physical conditions influencing subglacial lakes, sulfur and oxygen have shown that their mass exchange with the ice sheet above, chemoorganotrophicorheterotrophicgrowth and the consequences for both, lake and ice on ancientmarine organics coupledtoFe(III) dynamics. Subglacial lakes occur in specific or sulfate respiration drives a catalytic sulfur locations defined by subglacial topography and cycleresulting in asubglacial system that is the related effective hydrostaticpressure net iron reducing. As we move forward with distribution, ice dynamics and geothermal theexplorationofsubglacial systems, existing conditions. Thelakes physical conditions models, such as theTaylor Glacier system we depend on these parameters, which in return describe here, will provide important insight

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Program Book Final.pdf 22 3/3/2010 11:13:16 AM into ecosystem structure and function and will separated by three carousels of water samplers provide relevant toolsfor the examination of all attached to acentral flexible core that is the geomicrobiology of other subglacial attached to the tether. The bottom pressure environments. case houses the majority of the instrument package and is tipped with a short gravity core Probe Technologies forThe Direct sediment sampler (increasing total length to Measurement and Sampling of Subglacial ~4m). The upper pressure case contains the Lake Ellsworth power and communications link to the tether. Scientific return is ensured by the combined Mowlem, Matthew Mowlem Matthew Charles; useofinstrumentation returningreal-time FloquetCedric;Tsalogolou Maria-Nefeli; data,and acquisition of waterand sediment WaughEdward;FowlerLee; SawKevin M.C. samples for post-retrieval analyses.This Mowlem,C.Floquet, M. Tsalogolou,E.Waugh, provides redundancy, and enables informed L. Fowler, K. Saw, Underwater Systems deployment of the sampler systems. An Laboratory, National Oceanography Centre onboard microprocessorand data logger Southampton, Southampton, hampshire, enable continued operation(e.g. sampling at UNITED KINGDOM predetermined intervals) and archiving of instrument data in case of communications The direct measurement & sampling of failure.Power will be supplied both throughthe Subglacial Lake Ellsworth will be a tether and by onboard batteries,the latter multidisciplinary investigation of lifeinextreme being sufficient to complete the mission but environments and West Antarctic ice sheet with limited video footage. Probe-to-surface history. Theproject’s aims are : (1)to communications(two-way) will be viaan determine whether,and in what form, optical linkand backup wire modem using microbial life exists in Antarctic subglacial COTS technology used in several deep lakes, and (2) to reveal the post-Pliocene remotely-operated vehicles. The deployment in historyofthe West Antarctic IceSheet.An the field is scheduled for December 2012. extensive logisticsand equipment development programme will deliver the necessary Antarctic Subglacial Lake Discharges resourcesto thelocation of thelake. This will include novel hot waterdrill technology (for Pattyn, Frank PattynFrankF.Pattyn, lake access through ~3.4km of ice), a bespoke Laboratoire de Glaciologie, Universite Librede probe (to make measurement with sensors and Bruxelles, Brussels, BELGIUM to collect water and sediment samples), a gravity corer(to acquire alonger sediment Antarctic subglacial lakes were long time core) and a thermistor string for long term supposed to be relatively closed and stable monitoring of thelake. This paper details the environments with longresidence timesand design development of the probe system. This slow circulations. This view has recently been includes the instrumentation package, water challenged with evidence of active subglacial samplers and a mini gravity corer mounted on lake discharge underneaththe Antarctic ice the front of the probe. Supporting equipment sheet. Satellite altimetry observations required at the drill site to deploy and operate witnessed rapid changes in surface elevation the probe is also described. The project aims across subglacial lakes over periods ranging to complete theexperiment in aclean and from several months to more than a year, environmentally responsible manner in line which were interpreted as subglacial lake with principles set out by SCAR.The project discharge and subsequent lake filling, and will apply current knowledge of microbiological which seem to be acommonand widespread transfer and best practice in protection of feature. Although less impressive, such pristine environments. The design philosophy discharges are comparable to jökulhlaups and of the probe and systems is to minimise cost can be modelled that way using the Nye– andenhancereliability.To achieve this,the Röthlisberger theory. Subglacial water flow is number and complexity of elements is kept to driven by the hydraulic potential gradient, a minimum, and proven commercial off-the- which also controls when water will be driven shelf (COTS) technology is used wherever out of a subglacial cavity. Considering theice possible, limitingthe risk andcost of bespoke at the base of theice sheet at pressure melting system development.The probe is heavily point, subglacial conduits are sustainableover negatively buoyant, is tethered to the surface periods of more than ayear and over distances and has only simple manoeuvrability (depth of several hundreds of kilometers. control viatetherand limited rotation). The Furthermore,the theory is useful to predict the probe is ~3.5m in length and 20cmin diameter hydrograph defining lake filling and discharge. andconsist of two air-filled pressure cases In addition,couplingofanice sheet model to a

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Program Book Final.pdf 23 3/3/2010 11:13:16 AM subglacial lake system demonstrated that limited to larger kilometer-scale subglacial smallchanges in surfaceslopeare sufficientto lakes that are at least a meter thick. We startand sustainepisodicsubglacial drainage present the results of a series of synthetic events on decadal time scales.Therefore,lake seismic waveform modeling exercises which discharge may well be a common featureof suggest the possibility of detecting centimeter- thesubglacial hydrological system,influencing scalelayers of waterand dilatant till beneath the behavior of large ice sheets, especially the kilometers-thick ice. These modeling when subglacial lakes are perched at or near results demonstrate ameans forobtaining a the onset of large outlet glaciers and ice better snapshot of thedynamics of the basal streams. While most of the observed discharge regime,asthe subglacial plumbing system is events are relatively small(1E1-1E2m^3/s), likely important at the centimeter-scale. If evidence for larger subglacial discharges is seismic data are collected to capture the found in icefreeareas borderingAntarctica, various reflections from the ice-bed interface, and witnessing subglacial floodsof more than we can theoretically imagethe spatial 1E6 m^3/sthatoccurred between 14.4 and distribution of the subglacial water system, 12.4 Ma ago. especially in regionssurrounding known subglacial lakes, to better understandthe The Search for Life in FormerSubglacial connectivity of basal hydrologybeneath Lake Hodgson, Antarctica streaming ice. With synthetic seismic waveform modeling we predict the seismic Pearce, Alan Pearce David Anthony; Hodgson reflectivity of all four potential seismic Dominic; Cockell Charles D.A. Pearce,D. reflections for a basal layer, where we model Hodgson,, British Antarctic Survey, and determine the sensitivity of these seismic Cambridge, UNITED KINGDOM; C. Cockell, , waveforms to the thickness and material Open University,Milton Keynes, UNITED properties of the subglacial layer. The KINGDOM amplitude variation with source-receiver offset of these four basal reflections (pure Direct exploration of subglacial lakes in compressional wave reflection, pure shear Antarctica has yettobeachieved. However, at wave reflection,and the twoconverted wave the retreating margins of the ice sheet,there reflections) 'reflect' thecomposition of the are a number of accessiblelocations where subglacial bed, defined by its elastic properties former subglacial lakes are emerging from (compressional wave velocity, shear wave under the ice, but which remain perennially ice velocity, density). When a basal layeris covered. In this study, we describe the search greaterthan a quarter seismic wavelength forlifeinone such lake -Lake Hodgson thick, the reflections from the topand bottom (072°00.549'S, 068°27.708'W), which has of that layer are discernible, allowing the emerged from under more than 297-465 m of thickness and elastic properties of thebasal glacial ice during the last few thousand years. layerto be constrainedfromany oneofthe Surface sediment taken93.4m below the ice four potential basal reflections. For a thin surfacewas investigated usingacombination basal layer, whose thickness is less than a of epifluorescence microscopy, scanning quarter seismic wavelength, the reflections electron microscopy, fluorescence in situ from thetop and bottom of this layer interfere hybridization, clone library construction and with each other. Both a pure wave reflection analysis and direct culture. Results are and a converted wave reflection are needed to presented which include the presence or constrain the thickness and elastic properties absence of life, its characteristics and detection of thesubglacial bedinthisinstance. The limits. Theimplicationsfor future Antarctic striking observationfromthe modelingresults subglacial lake research are then discussed. is that the converted wave reflections exhibit a 180° phase shift in theirwaveforms whenonly Seismic Imaging of theSubglacial a centimeter of water or dilatant till is present, Plumbing System in comparision to no change in the seismic waveform of a pure wave reflection. This Peters, Leo Peters Leo E; Anandakrishnan phase shift demonstrates that converted wave SridharL.E. Peters, S. Anandakrishnan, reflections are quite sensitive to centimeter- Geosciences, ThePennsylvania State scalelayersofwater anddilatant till beneath University, University Park, PA theice.Thinlayersofwater matterinterms of what 'moves' the ice, as only a thin film of Subglacial wateris necessary forfast flowing basal water or dilatant till is needed to ice as it can lubricate glacier beds and lower overcome the asperities at the bed that may theirbasal shearstress. However, ourcurrent otherwise be inhibiting streaming iceflow.Our ability to image this hydrologicsystem is modelingresults highlight theability to capture

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Program Book Final.pdf 24 3/3/2010 11:13:16 AM basal hydrology at the centimeter-scale, increase of heliumconcentrationswith depthin thereby providing a means of imaging the the accreted ice impliesthe existence of subglacial plumbing system andhighlightingits sustained helium gradient in the lake, placing overall influenceinice dynamics. new constraints on water circulation and residence time.Itmay also representasteady New Helium Isotope Measurements in the degassing from the surrounding bedrock from Accreted Ice of the Subglacial Lake both a persistent tectonic activity, and radiogenic activity. In this respect a Petit, Jean Robert Jean Baptiste Philippe; Petit hydrothermal circulation in the deep faults is Jean Robert; Fourré Elise; Bulat Sergey; likely and may contribute to the survival of a Alekhina Irina; Lipenkov Vladimir P. Jean deep biosphere. Baptiste, E. Fourré,, Laboratoire des Sciences du Climat et de l’Environnement,CEA-Saclay, Assessing Grounding Zones and Sub-Ice- 91191 Gif-sur-Yvette,, FRANCE; J. Petit, , ShelfCavityProcessesUsing Direct Laboratoire de Glaciologie et Geophysique de Sampling and Robotic Instrumentation l'Environnement CNRS-UJF, 38402, St Martin d'Hères, FRANCE; S. Bulat, I. Alekhina,, Powell, Ross Powell Ross D; Team Rages Petersburg Nuclear Physics Institute RAS, ScienceR.D. Powell, R.S. Team, Geology and Leningrad Region,Gatchina, 188300 St. Environmental Geosciences, Northern Illinois Petersburg , RUSSIAN FEDERATION; V. Univ., DeKalb, IL Lipenkov, ,Arctic andAntarctic Research Institute, 19939, St Petersburg, RUSSIAN Grounding zones are seen as high priority FEDERATION targetsto investigate because models indicate these important areas strongly influence ice Helium is a well-known tracer in earth sheet stability and hence rates of future sea sciences. It has twoisotopes with contrasted level rise.Based on our present limited data proportionsinEarth’sreservoirs: 3Heis and modeling efforts, grounding zonescan be essentially primordial in origin whereas 4He is influenced by: (i) internal ice stream dynamics, produced by the radioactive decay of U and Th. (ii) rates of subglacial sediment (till) supply to When normalized to the atmospheric ratio (Ra the grounding zone, (iii) increased melting by =1.38 10-6),typical 3He/4Heratios vary from warming ocean waters, and/or (iv) <0.1 Ra in continental crust, to 8±1 Ra on filling/draining cycles of subglacial lakes. average in theupper mantle,and up to ~40- However, we do notcompletelyunderstand the 50 Ra in products of plume-related ocean full influence or details of theimportant islands, such as Hawaii andIceland,thought to processesingrounding zones. As one of three derive from thelower mantle.Here, we report components of anew project, WISSARD new helium isotope measurements in the (Whillans IceStreamSubglacial Access deepestice drilled from the accreted ice massif Research Drilling), RAGES (Robotic Access to of the subglacial Lake Vostok. Unlike most Grounding-zones for Exploration and Science) gases, helium can be incorporated into the research concentrates on the stability of the crystal structureofice during freezing,making grounding zone of the fast flowing Whillans Ice heliumisotopes in theaccreted iceavaluable Stream (WIS). RAGES is a first comprehensive source of information. Previous measurements attempt to investigateasub-ice-shelf cavity in (Jean-Baptiste et al., Nature 411, 2001) have these largelyunexplored systemsusing a shown a pronounced difference in both the complex array of newly designed and heliumconcentration andisotoperatio integrated instrumentation andfield between glacier iceand therefrozen lake operational equipment. The WIS grounding water, with atmospheric characteristics in the zone has been the target of recent remote glacier ice and a factor of 3 enrichment and a sensing and modeling studies(Anandakrishnan clear radiogenic signature from underlying the et al.2007; Alleyetal. 2007).These studies continental bedrock in the accreted ice ([4He] have shown that a sedimentary grounding- = 33.9±2.6 nmol/kg, R = 0.25±0.04 Ra). Our zone wedge is accumulating with aconsequent new data, from adepth range 3650.40 - thickening of theWIS such that icethickness 3656.37 m display even higher helium at the grounding line is greaterthan that of the concentrations ([4He] = 161±11 nmol/kg). hydrostatically-balanced floating ice of the Themeasuredisotopic 3He/4Heratios (R = Ross Ice Shelf. Thus the grounding line is 0.127±0.008 Ra) correspond to a mixture being stabilized and it will arguably remainin between atmospheric helium from the melted the same position until sea-level rise of at least glacier iceand crustalheliumadded to lake several meters overcomesthe excess ice waters with a radiogenic ratio R=0.007 Ra thickness (Anandakrishnanetal. 2007). typical of the upper continental crust. This Alternatively, either ocean melt of grounding-

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Program Book Final.pdf 25 3/3/2010 11:13:16 AM line iceor subglacial lake discharges may for a long-term record of ice sheet history). enhanceice discharge, both of which increase The exploration project will build, test and ice stream flow to thin the grounded ice faster deploy all the equipment necessary to than at present. RAGES will collect data to complete lake access, anddirectmeasurement assess this potentially critical situation. andsampling, in aclean andenvironmentally Further, Alleyetal. (2007) have argued that if responsible manner. Hot-water drilling will be this condition occurs around all Antarctic used to melt throughthe overlyingice.The grounding lines, then recent Antarctic ice chemistry, micro-biologyand physics of the volume changes (afterthe rapid initial post- lake environment will be investigated using a LGM retreat) cannot be attributed to sea-level custom-built clean probe. Real-time data rise, but rather are due to direct warming. acquisition during probedescent will provide Assessing the conditionsat WIS is therefore, flexibility for opportunistic sampling. After the primefor evaluating assertions that probe is recovered at thesurface acorer will synchronousbehavior of icesheetson be deployed forthe acquisition of alakefloor millennial time-scalesindicateice-sheet sediment core.Detailedsedimentological teleconnections by either sea level or climatic analysis of this core will be used to reveal forcing (cf. Alley et al. 2007; Naish et al.2009; changes in thelakeenvironment, andthe ice Pollard & DeConto 2009).http://wissard.org sheet, through time. This project will be a benchmark exercise in the exploration of Subglacial Lake Ellsworth: its History, Antarctica, andcould makeprofound scientific Recent Field Campaigns and Plans for its discoveries regarding life in extreme Exploration environments andWest Antarctic IceSheet history. Ross, Neil Ross Neil; Rivera Andrés; Siegert Martin John N. Ross, M.J. Siegert, School of A Sudden Outburst Flood Event Beneath GeoSciences, University of Edinburgh, Crane Glacier:Evidence, Causes, andIce Edinburgh, UNITED KINGDOM; A. Rivera, , Dynamic Effects Centro de Estudios Científicos, Valdivia, CHILE Scambos, Theodore Scambos Theodore A; Direct access, measurementand samplingof Berthier Etienne; Shuman Christopher AT.A. Subglacial Lake Ellsworth, West Antarcticais Scambos, National Snow and Ice Data planned for the 2012-13 Antarctic field season. Center/CIRES, University of Colorado, Boulder, This experiment aims to determine: i) the CO; C.A. Shuman,UMBC Goddard Earth presence, character and maintenance of Science and Technology Center, NASA Goddard microbiallifeinAntarctic subglacial lakes; and Space Flight Center, Greenbelt, MD; E. ii) the Quaternary historyof the West Antarctic Berthier, OMP-LEGOS, Centre National de la Ice Sheet (WAIS). Lake Ellsworth, first RechercheScienfifique, Toulouse, FRANCE observed in airborne radio-echo sounding data acquired in 1978, is located in a long, deep Recent studies have shown that sub-glacial subglacial trough located near theheadofthe lake activity can have a significantlocal effect Pine Island Glacier catchment ~30 km from on theflow speed of major outlet glacierson the central WAIS divide. Recent geophysical the greatice sheets(e.g.,Byrd Glacier:L. surveys have characterised the lake,its Stearns et al., 2008 Nature Geoscience). Here subglacial catchment and the thickness, we present an additional case where a large structure and flow of the overlying ice sheet. sub-glacial drainage appears to have causeda Seismic reflection data have revealed the lake significant change in ice flow speed. The event to be 156 m deep and underlain by was likely caused by the rapid elevation unconsolidated sediments. This fact,its changes on Crane Glacier. Crane Glacier in the physiographical setting within a well-defined Antarctic Peninsula has shown a remarkable steep topography and its location closeto a increase in speed (~8-fold) and decrease in logistics hub at Patriot Hills, makes thelake elevation (~150 m) since the break-up of the ideal for exploration. The seismic data have Larsen B Ice Shelf in 2002. However, during been used to define a preferred lake access the period November 2004 to November 2005, site at theintersectionbetween thecentral a portion of the lower glacier showed an axis of the lake and the downstream-most sudden, localized (~2km diameter) increase in seismic profile. At this point the lake is the rate of lowering, exceeding 100 m/year for characterised by: i) a relativelythin overlying a few months. The glacier accelerated at a ice column (~3.1 km); ii) a significant greaterrate during and afterthisperiod (as measured waterdepth(>145 m);iii) alake determined by a series of satellite image pairs floor sediment thickness of >2 m; and iv) low ending with Formosat-2 images in 2008 and sedimentation rates (increasing thelikelihood 2009),and the surface character of the lower

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Program Book Final.pdf 26 3/3/2010 11:13:16 AM glacier changed significantly to ahighly These sediments will provide microfossil data fractured serac field. Examination of the Crane to address hypotheses regarding ice sheet Glacier fjord bathymetry by multi-beam sonar history and subglacial processes, including in regions now exposed due to ice shelf and constraining icestreamsedimentfluxvia the glacier retreatshows aseriesofenclosed over- subglacial hydrological system and particle flux deepened basins.This suggests that a series of to the subglacial environment from englacial sub-glacial lakes existed in the lower trunk debris. Microfossils will contribute to these prior to ice shelf disintegration. The region of analyses, as well as providing a qualitative the large Crane elevation change is still ice- assessment of the intensity of subglacial covered and therefore unmapped for sediment shearing, basedon textural data and bathymetry,but may representanadditional morphologicfeaturesofthe sediment andits lacusterinebasin.Changingice surfaceslope fossils (Geology, 32, 557-511, 2004; J. in the years before the sudden drawdown can Nanotech. Nanosci., 5, 96-99, 2005; J. Sed. be inferred to have significantly changed the Geol.,68, 487-469, 1998). Over thenext sub-glacial hydrologic pressure field. In the several years, newdata from WISSARD, PIG, Crane Glacier case,acceleration during WAIS divide, and other projects may answer drainage may be driven by the largefurther not only Mercer’s first question,but improve increase in along-flow surfaceslopecausedby theassessment of thepotential forthe future drainage. disaster that he outlined.

What Can Tiny Fossils Eeach Us About ComparativeSubglacial Hydrology of WAIS History and Subglacial Processes? Thwaites Glacier, West Antarctica, Using Basal Specularity Scherer, Reed SchererReed PR.P. Scherer, Geology & Environmental Geosciences, Schroeder, Dustin Schroeder Dustin M; Northern Illinois University, De Kalb, IL BlankenshipDonaldD;Young Duncan AD.M. Schroeder, D.D. Blankenship, D.A. Young,, As we launch a new phase of subglacial and The University of Texas Institute for sub-iceshelf exploration andsamplingwith the Geophysics, Austin,TX WISSARDproject it seemsagoodtimeto review the type of data regarding ice sheet A key control on ice sheet response to climate history and subglacial processes that can be forcingisthe subglacial hydrologic boundary gleanedfrommicrofossils recoveredfromthe condition. Airborne ice penetrating radar subglacial and englacial environment. soundinghas been used with variable success Sediments, including short sediment cores, to identify and characterize subglacial were recovered from beneaththe southern hydrological systemsbythe strength of the Ross Ice Shelf in the 1970s (Ross Ice Shelf return from the basal interface. We present a Project Site J-9) andbeneath Ross icestreams means for improved characterization of in the 1990s (Upstream, Whillans and Kamb subglacial hydrology using multiple focusing icestreams). Some sub-icestreamsamples windows to separate the diffuse and specular include evidence of past retreatof the ice components of theinterface return.The sheet during thePleistocene.Fossil diatoms specularity content of the basal return can (marineplanktonic algae),with supporting indicate the presence and extent of subglacial evidence from cosmogenic-sourced 10Be in the water independentof temperature profile and sediments, provided evidence that open water impurity concentrationofthe icecolumn. We stretched across the West Antarctic interior at apply this technique to a gridded least once (though possibly multiple times) aerogeophysical survey over the confluence of during thelast ca. 1million years (Science, tributaries to Thwaites Glacier, West 281, 82-85, 1998; GRL, 35, 2008). Antarctica, a region of particular interest for its Unfortunately, a key hypothesis described by subglacial hydrology. In the context of John Mercer in his famous “Threat of Disaster” subglacial hydraulic gradients, we compare the paper (Nature, 271, 321-325, 1978) remains specularity at the confluence to that for each of equivocal:Did theWAIScollapseduringthe the tributaries as well as for the trunk and penultimate interglacial, 123 ka ago? We’ve grounding line. We also compare basal water learned alot about subglacial hydrology and system interpretations from specularity content marine ice sheet dynamics recently, but the to those from more traditional echo strength magnitude of fluxes, especially sediment flux analysis.This survey was collected using a 60 to the grounding line, remain conjectural. MHzcoherentice penetrating radar with a WISSARD will recover sediments from the linear frequency modulated waveform with a Grounding Zone (RAGES) and a subglacial lake 15 MHz bandwidth. We discuss the potential beneath theWhillans icestream(LISSARD). value of this approach forthe generalized

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Program Book Final.pdf 27 3/3/2010 11:13:16 AM characterization of basal water systems using likely to be as old as the ice sheet itself. The radar soundingdata. topographicsetting in which thelakesitsisfar older than the ice sheet and so we can expect Subglacial Lake Vostok:aReview of the lake to have developed at this site for as Geophysical Data Regarding Its long as the ice sheet has been at a continental Physiographical Setting size.This means thelakeis possiblyas old as 14 Ma.The age of the waterwithin the lake Siegert, Martin SiegertMartin John; Popov will be related to the age of the ice which melts Sergey; Studinger MichaelM.J. Siegert, into it, and thelevel of mixing that takes place. School of GeoSciences, University of Estimates put that combined age at around 1 Edinburgh, Edinburgh, UNITED KINGDOM; S. Ma. Popov, PMGE, 24, Pobeda str., St. Petersburg, RUSSIAN FEDERATION; M. Studinger, Lamont- The Identification And Physiographical Doherty Earth Observatory , Columbia Setting Of Antarctic Subglacial Lakes: An University, Palisides, NY Update Based On Recent Discoveries

Subglacial Lake Vostok is the largest and best Siegert, Martin Wright Andrew; Siegert Martin known sub-icelakeinAntarctica. The John A. Wright, M.J. Siegert, School of establishmentinthe 1990s of its waterdepth, GeoSciences, University of Edinburgh, at over 500m,led to an appreciation that such Edinburgh, UNITED KINGDOM environments may be habitats for life and may contain ancient records of ice sheet change. As We investigate the glaciological and a consequence, Lake Vostok catalyzed topographic setting of known Antarctic subglacial aquatic environment exploration and subglacial lakes (following a previous research. Here we discuss the discovery of the assessmentbyDowdeswell and Siegert, 2002, lake, and the various geophysical datasets based on the first inventory of 77 lakes). that, in combination, reveal the physiography Procedures used to detect subglacial lakes are of the lake. We also know discuss how these discussed, including radio-echo sounding (RES, data have led to an appreciation of the physical which wasfirst used to demonstrate the chemical andbiologicalprocesses in thelake. presence of subglacial lakes), surface The outline of the lake is known with a topography, topographical changes, gravity relatively high degree of accuracy, such that its measurements and seismic investigations. coastline and‘islands’ within thelakeare well Recent discoveriesofsubglacial lakesusing defined. The lake is over 250 km long and these techniques are detailed, from which a around 80 km wide in one place.Itlies revised new inventoryof subglacial lakesis beneath 4.2-3.7 km of ice, and exists because established, bringing the total number of background levels of geothermal heating are known subglacial lakesto 386. Using this new sufficient to warm the base of the icesheet to inventory, we examine various controls on the pressure melting value. Seismicdata, and subglacial lakes, such as overriding ice analysis of gravity measurements,showthe thickness and position within the ice sheet, and lake to have a bathymetry involving two formulate frequency distributionsfor theentire distinct basins. One is small (~2000 km3) and subglacial lake population based on these deep (~800 M) in the southern part of the (variable) controls. We show how theutility of lake,where the ice core is positioned, the RES in identifying subglacial lakes is spatially other larger region to the north(~10,000 affected; lakes away from theice divide are km3) is also relatively shallow (~300 m). noteasily detected by this technique, probably Analysis of theVostok icecorehas revealed due to scattering at the ice sheet base. We over 200 mof ice that has been accreted to show that subglacial lakes are widespread in the underside of the icesheet.Thisice has Antarctica, anditislikelythat manyare provided a valuable insight into the potential connected within well-defined subglacial biological and chemical setting of the lake. The hydrological systems. steady inclinationsof the ice-water interface (due to thelakebeing in hydrostatic Endurance: Two Missions to Antarctica equilibriumwith theice above),leads to and Paths to Advanced Sub-Glacial differential ice-base melting (in the north) Science Autonomy versus freezinginthe south, which excites circulation within thelakeand potential mixing Siegert, Martin Stone William C.; Richmond of the water column. The nature of such Kristof; Gulati Shilpa; Flesher Chris; Hogan circulation depends heavily on the chemical Bart; Murarka Aniket; Khulman Greg; Siegel propertiesofthe wateritself, whichisnot Victoria; Doran Peter T; Johnson Andrew E; known at this stage. The age of the lake is Obryck Maciej; Priscu John C; McKay

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Program Book Final.pdf 28 3/3/2010 11:13:16 AM Christopher PW.C. Stone, K. Richmond, S. system was comprisedofathreelayer filter Gulati, C. Flesher, B. Hogan, A. Murarka, G. utilizinghighgradedeadreckoning,ultrashort Khulman,V. Siegel, , StoneAerospace /PSC, baselinelocalization,and machine vision.Also Inc., Del Valle, TX; P.T. Doran, A.E. Johnson, new were web-based glacier imaging systems M. Obryck, Earth and Environmental Sciences, and a 120-degree swath high resolution multi- University of Illinois at Chicago, Chicago, IL; beam mapping sonar system – used for both J.C. Priscu, Department of LRES, Montana lake bottom and glacier face mapping. New State University, Boseman, MT; C.P. McKay,, power systems and a 3D situational awareness NASA Ames, Mountain View, CA system that incorporated all vehicle geometry sensors were added in time forthe 2009 West Permanently ice-covered liquid water Lake Bonney mission.Manyofthe environments are among the leading candidate characteristics and capabilities of ENDURANCE sitesfor findingevidenceofextant life –nowsuccessfully demonstrated in complex elsewhere in our solar system. In order to have under-ice settings beneath West Lake Bonney - the proper tools and strategies for exploring are the types of behaviorsthatwill be needed theextant ice-covered planetary for sub-ice autonomous probes to Europa, environments, we have developed an Enceladas, and other outer planet watery autonomousunderwatervehicle (AUV)named moons. ENDURANCE(Environmentally Non-Disturbing Under-ice Robotic ANtarctic Explorer). Microbial Communities in Antarctic ENDURANCEhas just completedthe second of Subglacial Aquatic Environments (SAE) two Antarctic field seasons with great success. Our new dataset for West Lake Bonney (WLB) Skidmore, Mark Skidmore Mark LM.L. includes hi-resolution sonarmapsofthe lake Skidmore, EarthSciences, Montana State including through the connecting channel and University, Bozeman,MT into East Lake Bonney,3Dtemperature, conductivity, pH, REDOX, photosynthetically Rock-water interactionsare fundamental to the active radiation, chl-a fluorometry and global geochemical cycles of manyelements, dissolved organic matter. The drop sonde including C, Fe, S, Si andP. These interactions science package also included a bottom imager are mediated by microbes in all Earth surface which collected 100’sofimages of the benthic environments, and theSAE of Arctic and Alpine microbial community and an upward looking glaciersand ice sheetsare no exception. camera captured information on sediment Glaciological processes under ice masses, distribution in theice cover. ENDURANCE is a including ice sheets provide sustainable habitat highly maneuverable, hovering autonomous for microbes, forming an aquatic environment underwater science platform descended from through basal melting and providing nutrients the DEPTHX vehicle, both of which were and energy from bedrock comminution. developed under NASA ASTEPfunding. Research over the past decade or so, largely ENDURANCE had thespecific mission of through remote sensingtechniques has descending through a 5 meter deep melt hole demonstrated the abundance of waterbeneath in the ice cap of West Lake Bonney, Taylor icesheets, includinglakes,channelized Valley, Antarctica and conducting three drainage systems andsaturated sediments and autonomous science tasks: 1) measuringthe has also highlighted the interconnectivity of 3D waterchemistry of thelake; 2) mapping these water bodies. Water is a key requirement the underwaterface of Taylor glacierwhere it for microbial life, and its abundance beneath enters the lake;and 3) charting the the Antarctic Ice Sheet indicates a significant bathymetry of thelakebottom;and then 4) volume of potential microbial habitat that is returning safely on its own to the melt hole – largelyunexplored. Sampling of SAE beneath barely 0.25 mlarger in diameterthanthe the Antarctic Ice Sheet especially for vehicle – from more than 2kilometersradial microbiological research hasbeen limited. range and rising up the hole to be retrieved for Examples areaccreted icefromsubglacial Lake data download and servicing for the next Vostok in East Antarcticaand saturated till mission. Included among these was the from beneath the ice streams draining the development of an automated sub-sea servo West Antarctic IceSheet.Viablemicrobes have winch and sonde payload with its nine water been detected in these samples and their chemistry probes, high definition imaging activity measured at temperatures closeto system, and bottom ranging altimeter.A freezing in the laboratory, demonstrating that specialized ice-picking behavior was developed in situ activity in subglacial environments is to maximizecast initialproximity to the plausible. Additional evidence forinsitu underside of the ice sheet and to reduce power subglacial microbial activity in saturated tills consumption during casts. Thenavigation comes from a) physical attributes of subglacial

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Program Book Final.pdf 29 3/3/2010 11:13:16 AM till particles that includeetchpits, often elsewhere in oursolarsystem(e.g. on Europa indicative of microbially-mediated mineral and other Galiean satellites). In order to have weathering and b) the geochemistry of the till the proper tools and strategies for exploring pore waters is consistent with biologically- theextant ice-covered planetary driven sulfideoxidation coupledto carbonate environments, we have developed an andsilicatemineral weathering as a significant autonomous underwater vehicle (AUV) which solute source. The diversity and activity of hasgenerated forthe firsttime, 3-D subglacial microbial communitiesdepends on biogeochemical datasets in theextreme the composition of the glacial flour, and the environment of perennially ice-covered content of labile organic matter, sulfides and Antarctic dry valley lakes. ENDURANCE Fe(III) in particular, which effects the Eh and (Environmentally Non-Disturbing Under-ice pH of the micro- and macro-environments. It Robotic ANtarctic Explorer) at thetime of also depends on the hydrological properties of writing this abstract is 3 days away from subglacial system components, that controls completing the second of two Antarctic field water-rock ratios,water-rockinteractiontimes seasons with greatsuccess. Ournew dataset and flow through rates,which in turn control for West Lake Bonney (WLB) includes the supplyof dissolved gases and movement of unprecedented hi-resolution sonarmapsofthe nutrients and waste products generated entirelake includingthrough the connecting through microbial activity. Key differences channeland into East Lake Bonney,3D(at 100 between Antarctic SAE and those beneath mxyand subcentimeter zresolution) Arctic and Alpine glaciersthathave been more temperature, conductivity, pH, REDOX, extensivelystudied arethe scale of the photosynthetically-active radiation, chl-a hydrological systems and their components, fluorometry and dissolved organic matter. The potential water residence times, which could drop sondescience packagealsoincluded a be ordersofmagnitude greaterinAntarctic bottom imager which collected 100’s of images systemsand thelack of connectivity between of the benthic microbial community and an oxygenated surface waters and the subglacial upward lookingcameracapturedinformation environment thus potentially leading to on sediment distribution in the ice cover. enhanced anoxic conditions in certain Variation in icethickness across thelakewas environments. These differences and their acquired both by sonarand pressure potential impact on microbial populations in transducer readings while thevehicle was at Antarctic SAE will also be discussed. rest under theice.Aforward lookingcamera in conjunction with swath sonar was used to Subglacial Drainage Events Under Outlet confirm the location of the ground line of Glacier End-members:ByrdGlacier and Taylor Glacier at thewest endofthe lake.Our Whillans Ice Stream preliminary assessment of the data suggests that thedepthofthe groundinglinecoincides Stearns, Leigh Stearns Leigh A; Fricker Helen with anomalous watercharacteristics near the Amanda L.A. Stearns, ,University of Kansas, glacier face, suggesting either a subglacial Lawrence, KS;H.A. Fricker, , Scripps discharge or some previously undocumented Institution of Oceanography, La Jolla, CA; mixing phenomenon.ENDURANCE is ahighly In the past 5 years, surprisingly active maneuverable, hovering autonomous networks of subglacial lakes have been found underwater science platform descended from beneath the Antarctic ice sheet.However, so the DEPTHX vehicle, both of which were farthe only linkbetween subglacial outburst developed under NASA ASTEPfunding. activity andglacier dynamics was observed on ENDURANCE had thespecific mission of Byrd Glacier. There, an outburst flood from two descending through a 5 meter deep melt hole relatively smalllakes released ~1.7 in theice cap of West Lake Bonney, Taylor km³ of water beneath Byrd Valley, Antarctica and conducting three Glacier, East Antarctica, andcaused a ~10 autonomous science tasks: 1) measuring the 3D waterchemistry of thelake; 2) mapping ENDURANCE: TwoMissions to Antarctica the underwaterface of Taylor glacierwhere it and Paths to Advanced Sub-Glacial enters the lake;and 3) charting the Science Autonomy bathymetry of thelakebottom;and then 4) returning safely on its own to the melt hole – Stone, William StoneWilliam C. W.C. Stone, , barely 0.25 mlarger in diameterthanthe Stone Aerospace, Del Valle, TX; vehicle – from more than 2kilometersradial range and rising up the hole to be retrieved for Permanently ice-covered liquid water data download and servicing for the next environments are among the leading candidate mission. Many of the characteristics and sitesfor findingevidenceofextant life capabilities of ENDURANCE – nowsuccessfully

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Program Book Final.pdf 30 3/3/2010 11:13:16 AM demonstrated in complex under-ice settings A 1-D model is used to calculate the past rates beneath West Lake Bonney -- are the types of of ice accumulation by internal layering. An behaviorsthatwill be needed forsub-ice approximate mean accumulation from 0.018 to autonomousprobes to Europa, Enceladas,and 0.027m/yr over the past 34.6k years, along other outerplanet watery moons. The the RES profiles, was estimated. Also, we have presentation will discuss all of the above along taken the accumulation was 0.02-0.045m/yr in with quantitativeengineering data on the the past 34.6-44.6kyr,and 0.01-0.023m/yr in design and field operation of the ENDURANCE the past 44.6-84.6kyr along the profile.The autonomousscience platform alongwith variability of accumulation in time-space advanced concepts forsub-ice autonomous around the ice divide also was given. science.www.stoneaerospace.com Enantiomer-specific IsotopeAnalysisfor Glaciological And Geophysical Studies in Chiral Amino Acids in AntarcticSub-glacial Dome A, East Antarctica Environment: Proposal

Sun, Bo Sun Bo;TangXueyuan; Li Xin; Cui Takano, Yoshinori Takano YoshinoriY. Takano, Xiangbin; Zhang Dong B. Sun, X. Tang, X. Li, Biogeoscience, JAMSTEC, Yokosuka, JAPAN X. Cui, D. Zhang,,PolarResearch Institute of China, Shanghai, CHINA Theone-handednessofterrestrial L-amino acids in the proteins and D-sugars of DNA and Dome A, located in the central East Antarctic RNA are essential to the formation, structure, icesheet (EAIS),isthe summit of theAntarctic and function of biopolymers for life on Earth. ice sheet. During the 21st and 24th Chinese D-amino acids such as D-alanineand D- National Antarctic Research Expedition glutamicacidare significant enantiomersthat (CHINARE 21, 2004/05;CHINARE 24, is physiologically essentialfor microbial growth 2007/08), ground-based ice radar systems and metabolic maintenance. Thenitrogen were used to athree-dimensional investigation isotopic difference Δ15ND-L (defined as in the central 30 km×30 km region at Dome A. δ15ND-Ala −δ15NL -Ala)inpeptidoglycan The obtained high resolution datasets were amino acids in bacteria such as Firmicutes and transferred and interpolatedinto the ice Actinobacteria (Enterococcus faecalis, thickness distribution ,subglacial topography Staphylococcus aureus, Staphylococcus and internal layers digital elevation model staphylolyticus, Lactobacillus acidophilus, (DEM).The results of the investigation indicate Bacillus subtilis,Micrococcus luteusand that the average ice thickness in the Dome A Streptomyces)tended to be N-depleted in D- central 30 km×30 km region is 2233 m, with a alanine(Δ15ND- −2.0‰). Theseresults minimal ice thickness of 1618 m and a suggest that thecomposition of isotopically maximum of 3139 m at Kunlun Station. The heterogeneous components in these bacteria is subglacial topography is relatively sharp, with primarily controlled by enzymatic pathways an elevation range of 949-2445 m. The typical prior to formation of the bacterial cell wall. In mountainglaciationmorphologyislikelyto contrast, theΔ15ND-L of racemic alanine, reflect theearly evolution of theAntarctic ice simplest chiral amino acid (C3), in the pristine sheet.The datasets also show some arches and chemical pathway during the nucleophilic troughs in isochronous ice layers. There exist substitution reaction (SN1 type, produce 50:50 some typical synclines and anticlines in ice racemic mixture) identifiedfully homogeneous revealed by ice-penetrating radar in some local components for each enantiomer. The regions. To characterizethe roughness from enantiomer-specific isotopic analysis (ESIA) bedrockand morphology of internal layers method is useful in determining theorigins of beneath ice sheets ,a two-parameter chirality in biogenic andabiogenic processes. roughness index is outlined, thetwo Consequently,ifthere is an abiotic synthesisof parameters are from not only FT of elevations, amino acids by hydrothermal reaction butalsoFTofsurface slopes.Geometric and processes in sub-glacial environment, glacier dynamical meanings of the roughness theoretically theΔ15ND-L will be homogeneous index are analyzed and discussed. It is shown components. References [1] Chikaraishi et al., that the method can be used to conveniently Determination of aquatic food-web structure demonstrates the spatialdistribution of based on compound-specific nitrogen isotopic roughness, without absence of statistically composition of amino acids: Limnology and geometric information, andcould be used to Oceanography: Methods, 7, 740-750 (2009). estimate the boundary condition such as basal [2] Takano et al., Compound-specific nitrogen slidinginglacier dynamics, or differentiate the isotopeanalysisofD-, L-alanineand valine: factors such as erosion/deposition or applicationofdiastereomerseparationto continental/marine settings in geomorphology. delta15N and microbial peptidoglycan studies:

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Program Book Final.pdf 31 3/3/2010 11:13:16 AM Analytical Chemistry, 81, 394-399 (2009). Chemistry Of Vostok Accretion Ice And Pore Waters Beneath The Kamb And Crustal UpliftingRateAssociatedWith Bindschadler Is Consistent With Microbial Late-Holocene Glacial-isostatic Rebound Life Beneath The Antarctic Ice Sheet at Skallenand Skarvsnes,Lützow-Holm Bay, East Antarctica: Evidence of a Tranter, Martyn Tranter Martyn M. Tranter, Synchrony in Sedimentary and Biological Bristol Glaciology Centre, University of Bristol, Facies on Geological Setting Bristol, 0, UNITED KINGDOM

Takano, Yoshinori Takano YoshinoriY. Takano, Interpretation of chemical variations in the Biogeosciences, JAMSTEC, Yokosuka, JAPAN accretion ice at the base of the Vostok Ice Core is controversial, sincesaline waters and We determined the mean crustal uplifting rate thermotectonic processesare required to during the late Holocene along the Soya Coast, account for the variations observed. Here, we Lützow-Holm Bay, East Antarctica, by dating a present amuchmoresimpleexplanation of the marine–lacustrine transition recorded in lake variations based on known geophysical sediments. We focused on temporal variations characteristics of thelake and simple water in the chemical composition of sediments and solute mass balance requirements. We recovered from Lake Skallen Oike at Skallen show that concentrated accretion ice should and Lake Oyako at Skarvsnes. Both sets of form over the embayment, since the lake sediments record environmental changes embayment is recharged only with relatively associated with atransition from marine to concentrated lake water, and that dilute lacustrine (fresh water) settings,as indicated accretion ice is formed over the open lake, by analyses of sedimentary facies for carbon since the lake is recharged with relatively and nitrogen contents, nitrogen isotopic dilute meteoric ice. Our estimated lake and compositions (15N/14N), and major element embayment water chemistries are consistent concentrations. Changes in thedominant with thepresenceofmicrobially-mediated primary producersduringthe marine– geochemical weathering within thelake. The lacustrine transition were also clearly revealed correspondence of higher microbial counts in by biogenic Opal-A, diatom assemblages, and themoreconcentratedaccretion iceis gradient gel electrophoresis (DGGE) with 16S consistent with thepresenceofmicrobesinthe rRNA gene analysis. Geochronology based on surfacewatersofthe Subglacial Lake Vostok. radiocarbon datingof acid-insoluble organic We compare and contrast the chemical carbon suggested that the environmental compositionsofthe Vostok waters with those transition from salineto fresh water occurred from tills beneath the Bindshadler and Kamb at 2940 ± 100 calyrBPatL.Skallenand 1060 Ice Streams. Again, the chemistry of the sub- ± 90 cal yr BP at L. Oyako. Based on these icestreamwatersisconsistent with the data and a linear approximation model, we presence of microbially-mediated geochemical estimated a mean crustal uplifting rate of 3.6 weathering reactions, particularly when mm yr–1 for the period since the marine– morphological and mineralogical evidence is lacustrine transition viabrackishcondition;this takeninto account.Together, this work uplift is attributed to glacial-isostatic rebound suggests that microbial life is present in the alongthe Soya Coast.Based on ages obtained spectrum waters that makeupthe sub-ice for the lowermost sediments (crustal sheet hydrological drainage system, which basement), initialsedimentation process includes subglacial lakesand theirinter- started by at least 5293–5559 cal yr BP (2σ) at connections. L. Skallenand by 1383–1610 cal yr BP (2σ) at L. Oyako. The geological setting was the Formation and Preservation of Long-Term primary factor in controlling the emergence Paleoclimatic and Paleoenvironmental event and the occurrence of simultaneous Records in Subglacial Lakes changes in sedimentary and biological facies alongthe zone of crustal uplift. This study is Tulaczyk, Slawek Tulaczyk Slawek S. useful to understandpast sub-glacial Tulaczyk,EarthSciences, University of environments during glacial-erosion processes. California, Santa Cruz, Santa Cruz, CA;

Lacustrine records provide the fundamental basis for building understanding of paleoenvironmental andpaleoclimatic evolution of non-glaciated continents over timescales ranging from sub-annual to millionsof years. Such records representan important spatial

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Program Book Final.pdf 32 3/3/2010 11:13:16 AM supplement to deep-sea andcontinental-shelf subglacial conditions. There are known marine sedimentary archives.InAntarctica, examples of Northern Hemisphere lake basins, ice cores and ice-marginal geologic records in which overriding ice sheet did not obliterate yielded a wealth of constraints on climatic and pre-glacial sedimentary sequences. environmental changes that took placeonthis continent, andglobally,inthe last fewmillion Microbial Responses During The years. Additional data sets are needed to Transition To Polar Night in Permanently extend thetemporal and spatial footprints of Ice-covered AntarcticLakes Trista J. Vick relevant observationalevidence.Sedimentary and John C. Priscu MontanaState sequences in Antarctic subglacial lakes will University, Department of Land Resources provide anew archive of paleoenvironmental and Environmental Science, 334 Leon and paleoclimatic records that may greatly Johnson Hall, Bozeman, Monta improve the existing understanding of Antarctic and global climate dynamics. Admittedly, Vick, Trista Vick Trista J; Priscu John CT.J. Antarctic subglacial lakes areisolated by thick Vick, J.C. Priscu, Land Resources and ice from direct atmospheric forcings and inputs Environmental Sciences, Montana State (e.g. dust, pollen, etc.), which are often used University, Bozeman,MT in reconstructing past climate and environmental changes. However, subglacial Amajority of theresearchonthe Antarctic lacustrine sedimentation should still be continent occurs during the austral spring and sensitive to long-term climate changes (over summer (October-January), a period of timescales >10kyrs) because subglacial continuous sunlight, when field support is hydrology is fundamentally tied to the readily available. Through additional logistical geometry, flow rates, and thethermal state of efforts, we were able to collect the first data on the ice sheet. These, in turn, are determined the MCM lakes during the transition from by climatic factors, such as mean annual summerto winter (October-April).A temperatures and accumulation rates. For combination of bacterial productivity data and instance, cold and dry climatic periods should 16S ribosomalRNA genetag sequence libraries result in low basal meltingrates andrelatively allowed us to examine ecosystem responses as sluggish inputs of basal meltwaterinto photosynthetic input of newcarbon stopped. subglacial lake basins.Inlacustrine records, Microbial proteinbiosynthesisincreased in the these conditions may be then reflected in east lobe of Lake Bonney and in Lake Hoare lowered sedimentation rates and reduced during March and April (p<0.05); therewas no maximum sediment grain size because reduced change in protein biosynthesis in the west lobe subglacial waterfluxeswill have lowered of Lake Bonney or in Lake Fryxell. DNA sedimentary capacity and competence. During replicationwas notaffected (p<0.05) by the warmer climatic periods, increased basal onset of complete darkness, inferring that the melting rates should lead to higher bacteria do not rely directly on phytoplankton sedimentation rates and larger maximum grain primary production as their source of organic sizes. Even though the ice sheet acts as a low- carbon during this period. A high rate of dark pass filter for climatic changes, Milankovitch- ¹⁴C-labeled bicarbonate scale climate variability has sufficiently long incorporation (0.01 to 0.09 µgC l^{- periodicity (>20kyr) to turn out to be a 1} d^-1)in oneofour recognizable driver of sedimentary variability study lakes (Lake Fryxell) implies that in subglacial lacustrine sequences chemoautotrophic primary production is accumulating over time periods covering important in sustaining the ecosystem of this hundreds of thousands to millions of years. lake during the winter. An overall decoupling This wouldenableapplicationofwell- of bacterial protein biosynthesis and DNA established orbitaltuning techniques to replication also occurred during the transition develop detailed timescales forsubglacial to winter. Protein biosynthesis increased lacustrine sequences. As in non-glaciated lake relative to DNA replication as darkness set in, basins,cyclic climateforcingsare likelytobe which may signifydecreasingrates of cell convolved in subglacial lake settings with local division. Such a shift in cellular function, in and regional factors that have to do with combinationwith continuedbacterial changes in interconnectivity of subglacial production, indicates that bacterioplankton in conduits, internal ice sheet dynamics, the MCM lakes remain active during the polar volcanic/geothermal events,orsubglacial night, butmay direct more energy towards erosionand sedimentation. Thevalue of survival than reproduction. Our results indicate Antarctic subglacial lacustrine records will be that concurrent measurement of protein greatly enhanced if such records contain synthesis andDNA synthesis in dark,sub-ice transition/s from/to pre-glacial to/from aquatic systems can provideimportant

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Program Book Final.pdf 33 3/3/2010 11:13:17 AM information on the physiological stateof the ExaminingThe PotentialFor microorganisms present. Methanogensis in AntarcticSubglacial Aquatic Environments On theRoleofSubglacial Bio/Geochemical Processes in Global Wadham, Jemma Wadham Jemma L; Stibal Biogeochemical Cycles -Results from Marek; Lis Grezegorz; Samyn Denis; Tison Kamb Ice Stream and ANDRILL Jean-Louis; Telling Jon; Anesio Alexandre; Dubnick Ashley; Sharp Martin J; Tranter Vogel, Stefan Vogel Stefan Willi S.W. Vogel,, Martyn; Lawson Emily J.L. Wadham, M. Northern Illinois University, De Kalb, IL Stibal, G. Lis, J. Telling, A. Anesio, M. Tranter, E. Lawson, School of Geographical Sciences, Subglacial environments play an important role University of Bristol, Bristol, UNITED forthe dynamicofice sheetsand global sea KINGDOM; D. Samyn, Glaciology Research level change. While subglacial environments Group, University of Uppsala, Uppsala, beneath alpine glaciersconsist of relatively Uppsala, SWEDEN; J. Tison, Faculte des small drainage systems, subglacial Sciences, Universite Libre de Bruxelles, environments in Antarctica and Greenland are Brussels, BELGIUM; A. Dubnick, M.J. Sharp, complexcontinental scale systems, which Department of Earth and Atmospheric directly connect to the ocean. Through intricate Sciences,University of Alberta,Edmonton, feedback mechanismsubglacial processes, Edmonton, Alberta, CANADA includingprocesses in thesub-ice-shelf cavity, influence global ocean circulation and Antarctic subglacial aquatic environments, contribute to thefertility of theocean.Herewe includingsubglacial lakes, areapreviously present the first geochemical measurements of neglected componentofthe Earth’scarbon basal water, porewaterand sediment cycle; areflection of theviewhelduntil recovered from the base of Kamb Ice Stream, recently that the basal regions of ice sheets West Antarctica and reviews them in the are dominated by abiotic and oxic conditions. context of global geochemical cycles and Here we consider thepotential of these potential contribution of subglacial environments as favourable habitats for environments to thefertilityofthe oceans.The methanogenic Archaea, and hence sites of results point to an oxygen depleted, sulfate methanogensis. We employ concentrationsof rich,acidicaquatic environment favorable to methane, carbondioxide and oxygen in basal the removal of sedimentary carbonate. The icefromthree glacier/ice sheet systems with removal of carbon and other nutrients from the contrastingorganic carbonsubstrates (Lower sediment and subsequent transport with the Wright Glacier, Antarctica; Russell Glacier, flow of basal water may constitute a significant Greenland Ice Sheet and Finsterwalderbreen, flux. Chemical processes across theice sheet Svalbard) in order to assess the methanogenic grounding zone, a zone of high saline gradients potential in Antarctic subglacial environments. (low solute freshwaterto high salineocean Concentrations of methane in debris rich basal water) may trigger either deposition of solutes ice exceed atmosphericconcentrations by up as observed in theANDRILL-MIS core, or to threeordersofmagnitude, carbondioxide furthermobilizationofnutrients from sediment concentrations are also elevated with respect as hypothesized for Fe with subsequent to atmospheric values and oxygen is depleted. distribution in the polar ocean. Overall These observations are consistent with a subglacial environments are farfrombeing diverse and active subglacial microbial understood and it is exciting that upcoming community, including heterotrophs and projects will be able to answer some of these methanogens. We go on to provide first questionsinthe near future.It is however evidence of the presence, diversity and important to properly understand the effect of abundance of methanogenic Archaea beneath sampling on sample chemistry when the Antarctic and Greenland ice sheets, interpreting the results of these projects. determined using a combination of microscopic Results from the ANDRILL porewater work and moleculartechniques. The abundance of indicateapost recovery shift of up to 1pH. Archaea in the subglacial sediment samples Notconsideringthe pressure and temperature from Antarctica and Greenland was between induced changes during recovery from a depth 10³ – 10⁵cells of 1000 m or more the results indicate the per gram of sediment,and most Archaea importance to combineinsitu measurements specific 16S rDNA clones were found to be with subsequent laboratory work. closeto uncultured clones from other types of cold environments, such as ice-covered lakes and permafrost peat. Between 40 and 60

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Program Book Final.pdf 34 3/3/2010 11:13:17 AM How Well Do Subglacial Lakes Act as Hydraulic Jacks?

Walter, Jacob Walter Jacob I; Tulaczyk Slawek M; Brodsky Emily E; Schwartz Susan YJ.I. Walter, S.M. Tulaczyk, E.E. Brodsky, S.Y. Schwartz, , University of California, Santa Cruz, Santa Cruz, CA

Recent evidence suggests that subglacial lake drainage promotes ice speed-ups(e.g. Stearns et al., 2008). While the drainage of large subglacial lakes may causefast ice-flow downstream, filled or filling subglacial lakes may promote faster flow over them by decreasing basal resistance to flow (Sergienko et al., 2008).Since December of 2007, we have operated a network of continuously operating GPS receiversonWhillansIce Stream (WIS), West Antarctica. The stations are located on,ornear, activesubglacial lakes, identified using IceSAT data (Fricker et al., 2007; Smith et al., 2009).We augmented the GPS network with passive broadband seismometers during the austral summers of 2007 and 2008,inorder to more closelystudy the bi-daily stick-slip events occurring on the lower part of WIS (Bindschadler et al., 2002). Our results indicate that the rupture speed of thestick-slip events is dependentuponthe frictional coupling of thebasal layer. Yet, the subglacial layer is not homogenous across all of WIS, as the subglacial lakes provide an important outlier. Preliminary results from two stations, one on Subglacial Lake Whillans (SLW)and another station~15 km from the SLWstation,indicatethat iceimmediatelyover SLW slips less during slip events, as compared to the adjacent off-lake station. However, the SLW ice flows faster in between slip events than the adjacent station, so that averaged over afew days,the SLWice flows8-9 cm/day faster than the adjacent station. If extrapolated, ourresults suggest icedirectly overlyingSLW flows~30 m/yr faster than adjacent ice. The differences in the nature of slip events and inter-event creep suggest a rapid basal transition over a mere ~15 km. Ourobservationsmay yieldimportant information regarding mechanics and dynamics of ice stream beds at the scaleof 10s of km.

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Program Book Final.pdf 35 3/3/2010 11:13:17 AM UpcomingChapman Meetings

Chapman Conference on Detachments in Oceanic Lithosphere: Deformation, Magmatism, Fluid Flow, and Ecosystems Agros, Cyprus 8–16 May 2010

Chapman Conference on Giant Earthquakes and Their Tsunamis Valparaíso, Viñadel Mar, and Valdivia, Chile 17–24 May 2010 (includes the 50th anniversary of the giant 1960 Chile earthquake and tsunami)

ChapmanConference on Climates, Past Landscapes, and Civilizations Santa Fe, New Mexico, USA 21–25 March, 2011

Chapman Conference on Source to Sink Around theWorld and Through Time: Recent Advances Understanding Production, Transfer and Burial of Terrestrial and Marine Materials on theEarth Surface Santa Barbara, California, USA January 2011

http://www.agu.org/meetings/chapman/

Program Book Final.pdf 36 3/3/2010 11:13:17 AM