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Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial 期刊论文
NATURE, 2020, 583 (7817) : 554-+
作者:  T. Blackburn;  G. H. Edwards;  S. Tulaczyk;  M. Scudder;  G. Piccione;  B. Hallet;  N. McLean;  J. C. Zachos;  B. Cheney;  J. T. Babbe
收藏  |  浏览/下载:19/0  |  提交时间:2020/08/09

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.


Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth'  s past interglacial warm periods(1-3). About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater(2)and sea level was 6 to 13 metres higher(1,3). Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet(3), which has been argued to have remained stable for millions of years before and includes MIS11(4,5). Here we show how the evolution of(234)U enrichment within the subglacial waters of East Antarctica recorded the ice sheet'  s response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of(234)U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of(234)U enrichment place the inception of this reservoir at MIS11. Informed by the(234)U cycling observed in the Laurentide Ice Sheet, where(234)U accumulated during periods of ice stability(6)and was flushed to global oceans in response to deglaciation(7), we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The(234)U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines(8-10), indicating(11)that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts(10)and bacteria(12)implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres(13)to global sea levels.


  
Twentieth Century Black Carbon and Dust Deposition on South Cascade Glacier, Washington State, USA, as Reconstructed From a 158-m-Long Ice Core 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (11)
作者:  Kaspari, S. D.;  Pittenger, D.;  Jenk, T. M.;  Morgenstern, U.;  Schwikowski, M.;  Buenning, N.;  Stott, L.
收藏  |  浏览/下载:16/0  |  提交时间:2020/08/18
light absorbing particles  black carbon  dust  ice core  cascades  melt  
Distributed Acoustic Sensing of Seismic Properties in a Borehole Drilled on a Fast-Flowing Greenlandic Outlet Glacier 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (13)
作者:  Booth, Adam D.;  Christoffersen, Poul;  Schoonman, Charlotte;  Clarke, Andy;  Hubbard, Bryn;  Law, Robert;  Doyle, Samuel H.;  Chudley, Thomas R.;  Chalari, Athena
收藏  |  浏览/下载:10/0  |  提交时间:2020/06/09
Distributed Acoustic Sensing (DAS)  Vertical Seismic Profile (VSP)  Greenland Ice Sheet  anisotropy  subglacial sediment  borehole surveying  
Continuity of the Mass Loss of the World's Glaciers and Ice Caps From the GRACE and GRACE Follow-On Missions 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (9)
作者:  Ciraci, E.;  Velicogna, I;  Swenson, S.
收藏  |  浏览/下载:10/0  |  提交时间:2020/07/02
gravity  glacier  sea level  climate model  hydrology  freshwater  
Calving Seasonality Associated With Melt-Undercutting and Lake Ice Cover 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (8)
作者:  Mallalieu, Joseph;  Carrivick, Jonathan L.;  Quincey, Duncan J.;  Smith, Mark W.
收藏  |  浏览/下载:8/0  |  提交时间:2020/07/02
calving  glacial lake  Greenland  outburst flood  structure-from-motion  time-lapse  
Sediment controls dynamic behavior of a Cordilleran Ice Stream at the Last Glacial Maximum 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Cowan, Ellen A.;  Zellers, Sarah D.;  Mueller, Juliane;  Walczak, Maureen H.;  Worthington, Lindsay L.;  Caissie, Beth E.;  Clary, Wesley A.;  Jaeger, John M.;  Gulick, Sean P. S.;  Pratt, Jacob W.;  Mix, Alan C.;  Fallon, Stewart J.
收藏  |  浏览/下载:9/0  |  提交时间:2020/05/13
Contrasting Centennial-Scale Climate Variability in High Mountain Asia Revealed by a Tree-Ring Oxygen Isotope Record From Lahaul-Spiti 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (4)
作者:  Managave, Shreyas;  Shimla, P.;  Yadav, Ram R.;  Ramesh, R.;  Balakrishnan, S.
收藏  |  浏览/下载:5/0  |  提交时间:2020/07/02
Early atmospheric contamination on the top of the Himalayas since the onset of the European Industrial Revolution 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (8) : 3967-3973
作者:  Gabrielli, Paolo;  Wegner, Anna;  Sierra-Hernandez, M. Roxana;  Beaudon, Emilie;  Davis, Mary;  Barker, Joel D.;  Thompson, Lonnie G.
收藏  |  浏览/下载:8/0  |  提交时间:2020/05/13
ice cores  trace metals  paleoenvironment  monsoon  North Atlantic Oscillation  
Lipid Biomarkers Quantify Holocene Summer Temperature and Ice Cap Sensitivity in Icelandic Lakes 期刊论文
GEOPHYSICAL RESEARCH LETTERS, 2020, 47 (3)
作者:  Harning, David J.;  39;Andrea, William J.
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/02
Precise radiometric age establishes Yarrabubba, Western Australia, as Earth's oldest recognised meteorite impact structure 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Erickson, Timmons M.;  Kirkland, Christopher L.;  Timms, Nicholas E.;  Cavosie, Aaron J.;  Davison, Thomas M.
收藏  |  浏览/下载:8/0  |  提交时间:2020/05/13