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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:21/0  |  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.


  
Climate From the McMurdo Dry Valleys, Antarctica, 1986-2017: Surface Air Temperature Trends and Redefined Summer Season 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Obryk, M. K.;  Doran, P. T.;  Fountain, A. G.;  Myers, M.;  McKay, C. P.
收藏  |  浏览/下载:6/0  |  提交时间:2020/08/18
McMurdo Dry Valleys  weather observations  summer season  
Diurnal Cycle of Precipitation Over the Maritime Continent Under Modulation of MJO: Perspectives From Cloud-Permitting Scale Simulations 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (13)
作者:  Wei, Yuntao;  Pu, Zhaoxia;  Zhang, Chidong
收藏  |  浏览/下载:9/0  |  提交时间:2020/08/18
tropical convection  diurnal cycle of precipitation  cloud-permitting simulation  MJO  
Attributing ozone and its precursors to land transport emissions in Europe and Germany 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (13) : 7843-7873
作者:  Mertens, Mariano;  Kerkweg, Astrid;  Volker, Grewe;  Joeckel, Patrick;  Sausen, Robert
收藏  |  浏览/下载:11/0  |  提交时间:2020/07/09
Spatiotemporal patterns of distributed slip in southern Owens Valley indicated by deformation of late Pleistocene shorelines, eastern California 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (7-8) : 1681-1703
作者:  Bacon, Steven N.;  Bullard, Thomas F.;  Keen-Zebert, Amanda K.;  Jayko, Angela S.;  Decker, David L.
收藏  |  浏览/下载:11/0  |  提交时间:2020/08/18
Pleistocene lakes and paleohydrologic environments of the Tecopa basin, California: Constraints on the drainage integration of the Amargosa River 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (7-8) : 1537-1565
作者:  Reheis, Marith C.;  Caskey, John;  Bright, Jordon;  Paces, James B.;  Mahan, Shannon A.;  Wan, Elmira
收藏  |  浏览/下载:10/0  |  提交时间:2020/08/18
A history of pore water oxygen isotope evolution in the Cretaceous Travis Peak Formation in East Texas 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (7-8) : 1626-1638
作者:  Denny, Adam C.;  Fall, Andras;  Orland, Ian J.;  Valley, John W.;  Eichhubl, Peter;  Laubach, Stephen E.
收藏  |  浏览/下载:5/0  |  提交时间:2020/08/18
Warming and monsoonal climate lead to large export of millennial-aged carbon from permafrost catchments of the Qinghai-Tibet Plateau 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2020, 15 (7)
作者:  Song, Chunlin;  Wang, Genxu;  Haghipour, Negar;  Raymond, Peter A.
收藏  |  浏览/下载:10/0  |  提交时间:2020/08/18
riverine carbon export  radiocarbon  stable carbon isotope  permafrost  Qinghai-Tibet Plateau river  climate warming  
Ozone Production in the Soberanes Smoke Haze: Implications for Air Quality in the San Joaquin Valley During the California Baseline Ozone Transport Study 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2020, 125 (11)
作者:  Langford, Andrew O.;  Alvarez, Raul J., II;  Brioude, J.;  Caputi, Dani;  Conley, Stephen A.;  Evan, S.;  Faloona, Ian C.;  Iraci, Laura T.;  Kirgis, Guillaume;  Marrero, Josette E.;  Ryoo, Ju-Mee;  Senff, Christoph J.;  Yates, Emma L.
收藏  |  浏览/下载:14/0  |  提交时间:2020/08/18
ozone  wildfire  lidar  aircraft  California  San Joaquin Valley  
How canyons evolve by incision into bedrock: Rainbow Canyon, Death Valley National Park, United States 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (26) : 14730-14737
作者:  Zhang, Li;  Li, Tiejian;  Wang, Guangqian;  Kwang, Jeffrey S.;  Nittrouer, Jeffrey A.;  Fu, Xudong;  Parker, Gary
收藏  |  浏览/下载:10/0  |  提交时间:2020/06/22
canyon  bedrock  incision  uplift  knickpoint