Were West Antarctic Ice Sheet Grounding Events in the Ross Sea a Consequence of East Antarctic Ice Sheet Expansion During the Middle Miocene?
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T Antarctic Ce Sheet Itiative
race Publication 3115, Vol. 1 t Antarctic ce Sheet itiative :_,.me.-1: Science and ;mentation Plan iv-_J_ E -- --__o • E _-- rz " _ • _ _v_-- . "2-. .... E _ ____ __ _k - -- - ...... --rr r_--_.-- .... m-- _ £3._= --- - • ,r- ..... _ k • -- ..... __= ---- = ............ --_ m -- -- ..... Z Im .... r .... _,... ___ "--. 11 1"1 I' I i ¸ NASA Conference Publication 3115, Vol. 1 West Antarctic Ice Sheet Initiative Volume 1: Science and Implementation Plan Edited by Robert A. Bindschadler NASA Goddard Space Flight Center Greenbelt, Maryland Proceedings of a workshop cosponsored by the National Aeronautics and Space Administration, Washington, D.C., and the National Science Foundation, Washington, D.C., and held at Goddard Space Flight Center Greenbelt, Maryland October 16-18, 1990 IXl/_/X National Aeronautics and Space Administration Office of Management Scientific and Technical Information Division 1991 CONTENTS Page Preface v Workshop Participants vi Acknowledgements vii Map viii 1. Executive Summary 1 2. Climatic Importance of Ice Sheets 4 3. Marine Ice Sheet Instability 5 4. The West Antarctic Ice Sheet Initiative 6 4.1 Goal and Objectives 6 4.2 A Multidisciplinary Project 7 4.3 Scientific Focus: A Single Goal 7 4.4 Geographic Focus: West Antarctica 7 4.5 Duration: A Phased Approach 8 5. Science Plan 10 5.1 Glaciology 10 5.1.1 Ice Dynamics 10 5.1.2 Ice Cores 16 5.2 Meteorology 19 5.3 Oceanography 23 5.4 Geology and Geophysics 27 5.4.1 Terrestrial Geology 27 5.4.2 Marine Geology and Geophysics 28 5.4.3 Subglacial Geology and Geophysics 30 6. -
Rapid Cenozoic Glaciation of Antarctica Induced by Declining
letters to nature 17. Huang, Y. et al. Logic gates and computation from assembled nanowire building blocks. Science 294, Early Cretaceous6, yet is thought to have remained mostly ice-free, 1313–1317 (2001). 18. Chen, C.-L. Elements of Optoelectronics and Fiber Optics (Irwin, Chicago, 1996). vegetated, and with mean annual temperatures well above freezing 4,7 19. Wang, J., Gudiksen, M. S., Duan, X., Cui, Y. & Lieber, C. M. Highly polarized photoluminescence and until the Eocene/Oligocene boundary . Evidence for cooling and polarization sensitive photodetectors from single indium phosphide nanowires. Science 293, the sudden growth of an East Antarctic Ice Sheet (EAIS) comes 1455–1457 (2001). from marine records (refs 1–3), in which the gradual cooling from 20. Bagnall, D. M., Ullrich, B., Sakai, H. & Segawa, Y. Micro-cavity lasing of optically excited CdS thin films at room temperature. J. Cryst. Growth. 214/215, 1015–1018 (2000). the presumably ice-free warmth of the Early Tertiary to the cold 21. Bagnell, D. M., Ullrich, B., Qiu, X. G., Segawa, Y. & Sakai, H. Microcavity lasing of optically excited ‘icehouse’ of the Late Cenozoic is punctuated by a sudden .1.0‰ cadmium sulphide thin films at room temperature. Opt. Lett. 24, 1278–1280 (1999). rise in benthic d18O values at ,34 million years (Myr). More direct 22. Huang, Y., Duan, X., Cui, Y. & Lieber, C. M. GaN nanowire nanodevices. Nano Lett. 2, 101–104 (2002). evidence of cooling and glaciation near the Eocene/Oligocene 8 23. Gudiksen, G. S., Lauhon, L. J., Wang, J., Smith, D. & Lieber, C. M. Growth of nanowire superlattice boundary is provided by drilling on the East Antarctic margin , structures for nanoscale photonics and electronics. -
Asynchronous Antarctic and Greenland Ice-Volume Contributions to the Last Interglacial Sea-Level Highstand
ARTICLE https://doi.org/10.1038/s41467-019-12874-3 OPEN Asynchronous Antarctic and Greenland ice-volume contributions to the last interglacial sea-level highstand Eelco J. Rohling 1,2,7*, Fiona D. Hibbert 1,7*, Katharine M. Grant1, Eirik V. Galaasen 3, Nil Irvalı 3, Helga F. Kleiven 3, Gianluca Marino1,4, Ulysses Ninnemann3, Andrew P. Roberts1, Yair Rosenthal5, Hartmut Schulz6, Felicity H. Williams 1 & Jimin Yu 1 1234567890():,; The last interglacial (LIG; ~130 to ~118 thousand years ago, ka) was the last time global sea level rose well above the present level. Greenland Ice Sheet (GrIS) contributions were insufficient to explain the highstand, so that substantial Antarctic Ice Sheet (AIS) reduction is implied. However, the nature and drivers of GrIS and AIS reductions remain enigmatic, even though they may be critical for understanding future sea-level rise. Here we complement existing records with new data, and reveal that the LIG contained an AIS-derived highstand from ~129.5 to ~125 ka, a lowstand centred on 125–124 ka, and joint AIS + GrIS contributions from ~123.5 to ~118 ka. Moreover, a dual substructure within the first highstand suggests temporal variability in the AIS contributions. Implied rates of sea-level rise are high (up to several meters per century; m c−1), and lend credibility to high rates inferred by ice modelling under certain ice-shelf instability parameterisations. 1 Research School of Earth Sciences, The Australian National University, Canberra, ACT 2601, Australia. 2 Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton SO14 3ZH, UK. 3 Department of Earth Science and Bjerknes Centre for Climate Research, University of Bergen, Allegaten 41, 5007 Bergen, Norway. -
West Antarctic Ice Sheet Divide Ice Core Climate, Ice Sheet History, Cryobiology
QUARTERLY UPDATE August 2009 West Antarctic Ice Sheet Divide Ice Core Climate, Ice Sheet History, Cryobiology 2009/2010 Field Operations Our main objectives for the coming field season are: 1) To ship ice from 680 to ~2,100 m to NICL 2) Recover core to a depth of 2,600 to 2,900 m The U.S. Antarctic Program will be establishing a multi year field camp at Byrd this season to support field operations around Pine Island Bay and elsewhere in West Antarctica. The camp at Byrd will complicate our logistics because the heavy equipment that will prepare the Byrd skiway will be flown to WAIS Divide and driven to Byrd, and a camp at Byrd will make for more competition for flights. But this is a much better plan than supporting those operations out of WAIS Divide, which would have increased the WAIS Divide population to 100 people. Other science activities at WAIS Divide this season include the following: CReSIS ground traverse to Pine Island Bay Flow dynamics of two Amundsen Sea glaciers: Thwaites and Pine Island. PI: Anandakrishnan Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica. PI: Joughin Space physics magnetometer. PI: Zesta Antarctic Automatic Weather Station Program. PI: Weidner Polar Experiment Network for Geospace Upper atmosphere Investigations. PI: Lessard Artist, paintings of ice and glacial features. PI: McKee IDDO is making several modifications to the drill that should increase the amount of core that can be recovered each time the drill is lowered into the hole, which will increase the amount of ice we can recover this season. -
GSA TODAY • Southeastern Section Meeting, P
Vol. 5, No. 1 January 1995 INSIDE • 1995 GeoVentures, p. 4 • Environmental Education, p. 9 GSA TODAY • Southeastern Section Meeting, p. 15 A Publication of the Geological Society of America • North-Central–South-Central Section Meeting, p. 18 Stability or Instability of Antarctic Ice Sheets During Warm Climates of the Pliocene? James P. Kennett Marine Science Institute and Department of Geological Sciences, University of California Santa Barbara, CA 93106 David A. Hodell Department of Geology, University of Florida, Gainesville, FL 32611 ABSTRACT to the south from warmer, less nutrient- rich Subantarctic surface water. Up- During the Pliocene between welling of deep water in the circum- ~5 and 3 Ma, polar ice sheets were Antarctic links the mean chemical restricted to Antarctica, and climate composition of ocean deep water with was at times significantly warmer the atmosphere through gas exchange than now. Debate on whether the (Toggweiler and Sarmiento, 1985). Antarctic ice sheets and climate sys- The evolution of the Antarctic cryo- tem withstood this warmth with sphere-ocean system has profoundly relatively little change (stability influenced global climate, sea-level his- hypothesis) or whether much of the tory, Earth’s heat budget, atmospheric ice sheet disappeared (deglaciation composition and circulation, thermo- hypothesis) is ongoing. Paleoclimatic haline circulation, and the develop- data from high-latitude deep-sea sed- ment of Antarctic biota. iments strongly support the stability Given current concern about possi- hypothesis. Oxygen isotopic data ble global greenhouse warming, under- indicate that average sea-surface standing the history of the Antarctic temperatures in the Southern Ocean ocean-cryosphere system is important could not have increased by more for assessing future response of the Figure 1. -
S41467-018-05625-3.Pdf
ARTICLE DOI: 10.1038/s41467-018-05625-3 OPEN Holocene reconfiguration and readvance of the East Antarctic Ice Sheet Sarah L. Greenwood 1, Lauren M. Simkins2,3, Anna Ruth W. Halberstadt 2,4, Lindsay O. Prothro2 & John B. Anderson2 How ice sheets respond to changes in their grounding line is important in understanding ice sheet vulnerability to climate and ocean changes. The interplay between regional grounding 1234567890():,; line change and potentially diverse ice flow behaviour of contributing catchments is relevant to an ice sheet’s stability and resilience to change. At the last glacial maximum, marine-based ice streams in the western Ross Sea were fed by numerous catchments draining the East Antarctic Ice Sheet. Here we present geomorphological and acoustic stratigraphic evidence of ice sheet reorganisation in the South Victoria Land (SVL) sector of the western Ross Sea. The opening of a grounding line embayment unzipped ice sheet sub-sectors, enabled an ice flow direction change and triggered enhanced flow from SVL outlet glaciers. These relatively small catchments behaved independently of regional grounding line retreat, instead driving an ice sheet readvance that delivered a significant volume of ice to the ocean and was sustained for centuries. 1 Department of Geological Sciences, Stockholm University, Stockholm 10691, Sweden. 2 Department of Earth, Environmental and Planetary Sciences, Rice University, Houston, TX 77005, USA. 3 Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22904, USA. 4 Department -
West Antarctic Ice Sheet Divide Ice Core Climate, Ice Sheet History, Cryobiology
WAIS DIVIDE SCIENCE COORDINATION OFFICE West Antarctic Ice Sheet Divide Ice Core Climate, Ice Sheet History, Cryobiology A GUIDE FOR THE MEDIA AND PUBLIC Field Season 2011-2012 WAIS (West Antarctic Ice Sheet) Divide is a United States deep ice coring project in West Antarctica funded by the National Science Foundation (NSF). WAIS Divide’s goal is to examine the last ~100,000 years of Earth’s climate history by drilling and recovering a deep ice core from the ice divide in central West Antarctica. Ice core science has dramatically advanced our understanding of how the Earth’s climate has changed in the past. Ice cores collected from Greenland have revolutionized our notion of climate variability during the past 100,000 years. The WAIS Divide ice core will provide the first Southern Hemisphere climate and greenhouse gas records of comparable time resolution and duration to the Greenland ice cores enabling detailed comparison of environmental conditions between the northern and southern hemispheres, and the study of greenhouse gas concentrations in the paleo-atmosphere, with a greater level of detail than previously possible. The WAIS Divide ice core will also be used to test models of WAIS history and stability, and to investigate the biological signals contained in deep Antarctic ice cores. 1 Additional copies of this document are available from the project website at http://www.waisdivide.unh.edu Produced by the WAIS Divide Science Coordination Office with support from the National Science Foundation, Office of Polar Programs. 2 Contents -
Download Factsheet
Antarctic Factsheet Geographical Statistics May 2005 AREA % of total Antarctica - including ice shelves and islands 13,829,430km2 100.00% (Around 58 times the size of the UK, or 1.4 times the size of the USA) Antarctica - excluding ice shelves and islands 12,272,800km2 88.74% Area ice free 44,890km2 0.32% Ross Ice Shelf 510,680km2 3.69% Ronne-Filchner Ice Shelf 439,920km2 3.18% LENGTH Antarctic Peninsula 1,339km Transantarctic Mountains 3,300km Coastline* TOTAL 45,317km 100.00% * Note: coastlines are fractal in nature, so any Ice shelves 18,877km 42.00% measurement of them is dependant upon the scale at which the data is collected. Coastline Rock 5,468km 12.00% lengths here are calculated from the most Ice coastline 20,972km 46.00% detailed information available. HEIGHT Mean height of Antarctica - including ice shelves 1,958m Mean height of Antarctica - excluding ice shelves 2,194m Modal height excluding ice shelves 3,090m Highest Mountains 1. Mt Vinson (Ellsworth Mts.) 4,892m 2. Mt Tyree (Ellsworth Mts.) 4,852m 3. Mt Shinn (Ellsworth Mts.) 4,661m 4. Mt Craddock (Ellsworth Mts.) 4,650m 5. Mt Gardner (Ellsworth Mts.) 4,587m 6. Mt Kirkpatrick (Queen Alexandra Range) 4,528m 7. Mt Elizabeth (Queen Alexandra Range) 4,480m 8. Mt Epperly (Ellsworth Mts) 4,359m 9. Mt Markham (Queen Elizabeth Range) 4,350m 10. Mt Bell (Queen Alexandra Range) 4,303m (In many case these heights are based on survey of variable accuracy) Nunatak on the Antarctic Peninsula 1/4 www.antarctica.ac.uk Antarctic Factsheet Geographical Statistics May 2005 Other Notable Mountains 1. -
Obliquity-Paced Pliocene West Antarctic Ice Sheet Oscillations
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Earth and Atmospheric Sciences, Department Papers in the Earth and Atmospheric Sciences of 2009 Obliquity-paced Pliocene West Antarctic ice sheet oscillations T. Naish Victoria University of Wellington R. D. Powell Northern Illinois University, [email protected] R. Levy University of Nebraska-Lincoln G. Wilson University of Otago R. Scherer Northern Illinois University See next page for additional authors Follow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences Commons Naish, T.; Powell, R. D.; Levy, R.; Wilson, G.; Scherer, R.; Talarico, F.; Krissek, L.; Niessen, F.; Pompilio, M.; Wilson, T. J.; Carter, L.; DeConto, R.; Huybers, P.; McKay, R.; Pollard, D.; Ross, J.; Winter, D.; Barrett, P.; Browne, G.; Cody, R.; Cowan, E. A.; Crampton, J.; Dunbar, G.; Dunbar, N.; Florindo, F.; Gebhardt, C.; Graham, I.; Hannah, M.; Hansaraj, D.; Harwood, David M.; Helling, D.; Henrys, S.; Hinnov, L.; Kuhn, G.; Kyle, P.; La¨ufer, A.; Maffioli,.; P Magens, D.; Mandernack, K.; McIntosh, W.; Millan, C.; Morin, R.; Ohneiser, C.; Paulsen, T.; Persico, D.; Raine, I.; Reed, J.; Riesselman, C.; Sagnotti, L.; Schmitt, D.; Sjunneskog, C.; Strong, P.; Taviani, M.; Vogel, S.; Wilch, T.; and Williams, T., "Obliquity-paced Pliocene West Antarctic ice sheet oscillations" (2009). Papers in the Earth and Atmospheric Sciences. 185. https://digitalcommons.unl.edu/geosciencefacpub/185 This Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. -
Provenance Signatures of the Antarctic Ice Sheets in the Ross Embayment During the Late Miocene to Early Pliocene: the ANDRILL AND-1B Core Record
University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln ANDRILL Research and Publications Antarctic Drilling Program 11-2009 Provenance signatures of the Antarctic Ice Sheets in the Ross Embayment during the Late Miocene to Early Pliocene: The ANDRILL AND-1B core record Franco M. Talarico Università di Siena, [email protected] Sonia Sandroni Università di Siena, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/andrillrespub Part of the Environmental Indicators and Impact Assessment Commons Talarico, Franco M. and Sandroni, Sonia, "Provenance signatures of the Antarctic Ice Sheets in the Ross Embayment during the Late Miocene to Early Pliocene: The ANDRILL AND-1B core record" (2009). ANDRILL Research and Publications. 49. https://digitalcommons.unl.edu/andrillrespub/49 This Article is brought to you for free and open access by the Antarctic Drilling Program at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in ANDRILL Research and Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Published in Global and Planetary Change 69:3 (November 2009), pp. 103–123; doi:10.1016/j.gloplacha.2009.04.007 Copyright © 2009 Elsevier B.V. Used by permission. Submitted December 23, 2008; accepted April 22, 2009; published online May 4, 2009. Provenance signatures of the Antarctic Ice Sheets in the Ross Embayment during the Late Miocene to Early Pliocene: The ANDRILL AND-1B core record F. M. Talarico Dipartimento di Scienze della Terra, Università di Siena, Via Laterina 8, Siena, Italy (Corresponding author; tel 39 577233812, fax 39 577233938, email [email protected] ) S. Sandroni Museo Nazionale dell’Antartide, Università di Siena, Via Laterina 8, Siena, Italy Abstract Significant down-core modal and compositional variations are described for granule- to cobble-sized clasts in the Early Pliocene to Middle/Late Miocene sedimentary cycles of the AND-1B drill core at the NW edge of the Ross Ice Shelf (McMurdo Sound). -
Antarctic Ice Sheet Computer Animations and Paper Model by Tau Rho Alpha, and Alan K
Go Home U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY Antarctic Ice Sheet Computer animations and paper model By Tau Rho Alpha, and Alan K. Cooper Open-file Report 98-353 fl This report is preliminary and has not been reviewed for conformity with U.S. Geological Survey editorial standards. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this program has been used by the U.S. Geological Survey, no warranty, expressed or implied, is made by the USGS as to the accuracy and functioning of the program and related program material, nor shall the fact of distribution constitute any such warranty, and no responsibility is assumed by the USGS in connection therewith. U.S. Geological Survey Menlo Park, CA 94025 Comments encouraged [email protected] [email protected] 1998 (go backward) <T"1 L^ (go forward) Description of Report This report illustrates, through computer animation and a paper model, why there are changes on the ice sheet that covers the Antarctica continent. By studying the animations and the paper model, students will better understand the evolution of the Antarctic ice sheet. Included in the paper and diskette versions of this report are templates for making a papetfttiodel, instructions for its assembly, and a discussion of development of the Antarctic ice sheet. In addition, the diskette version includes a animation of how Antarctica and its ice cover changes through time. Many people provided help and encouragement in the development of this HyperCard stack, particularly Page Mosier, Sue Priest and Art Ford. -
Energetics of Surface Melt in West Antarctica Madison L
https://doi.org/10.5194/tc-2020-311 Preprint. Discussion started: 28 October 2020 c Author(s) 2020. CC BY 4.0 License. Energetics of Surface Melt in West Antarctica Madison L. Ghiz1, Ryan C. Scott2, Andrew M. Vogelmann3, Jan T. M. Lenaerts4, Matthew Lazzara5, Dan Lubin1 1Scripps Institution of Oceanography, University of California San Diego, La Jolla CA 92093-0206 USA 5 2NASA Langley Research Center, Hampton VA 23666 USA 3Environmental and Climate Sciences Department, Brookhaven National Laboratory, Upton NY 11973-5000 USA 4Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder CO 80309-0311 USA 5Antarctic Meteorological Research Center, SSEC, University of Wisconsin, Madison WI 53706 USA Correspondence to: Dan Lubin ([email protected]) 10 Abstract. We use reanalysis data and satellite remote sensing of cloud properties to examine how meteorological conditions alter the surface energy balance to cause surface melt that is detectable in satellite passive microwave imagery over West Antarctica. This analysis can detect each of the three primary mechanisms for inducing surface melt at a specific location: thermal blanketing involving sensible heat flux and/or longwave heating by optically thick cloud cover, all-wave radiative enhancement by optically thin cloud cover, and föhn winds. We examine case studies over Pine Island and Thwaites Glaciers, 15 which are of interest for ice shelf and ice sheet stability, and over Siple Dome, which is more readily accessible for field work. During January 2015 over Siple Dome we identified a melt event whose origin is an all-wave radiative enhancement by optically thin clouds. During December 2011 over Pine Island and Thwaites Glaciers, we identified a melt event caused mainly by thermal blanketing from optically thick clouds.