GSTDTAP

浏览/检索结果: 共140条,第1-10条 帮助

限定条件    
已选(0)清除 条数/页:   排序方式:
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.


  
Upper Midwest lakes are supersaturated with N-2 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (29) : 17063-17067
作者:  Loeks-Johnson, Brianna M.;  Cotner, James B.
收藏  |  浏览/下载:21/0  |  提交时间:2020/07/09
denitrification  nitrogen fixation  nitrogen cycling  biogeochemistry  
A new marine biogenic emission: methane sulfonamide (MSAM), dimethyl sulfide (DMS), and dimethyl sulfone (DMSO2) measured in air over the Arabian Sea 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (10) : 6081-6094
作者:  Edtbauer, Achim;  Stoenner, Christof;  Pfannerstill, Eva;  Berasategui, Matias;  Walter, David;  Crowley, John N.;  Lelieveld, Jos;  Williams, Jonathan
收藏  |  浏览/下载:9/0  |  提交时间:2020/06/01
Invasive earthworms unlock arctic plant nitrogen limitation 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Blume-Werry, Gesche;  Krab, Eveline J.;  Olofsson, Johan;  Sundqvist, Maja K.;  Vaisanen, Maria;  Klaminder, Jonatan
收藏  |  浏览/下载:11/0  |  提交时间:2020/05/13
Global inorganic nitrate production mechanisms: comparison of a global model with nitrate isotope observations 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (6) : 3859-3877
作者:  Alexander, Becky;  Sherwen, Tomas;  Holmes, Christopher D.;  Fisher, Jenny A.;  Chen, Qianjie;  Evans, Mat J.;  Kasibhatla, Prasad
收藏  |  浏览/下载:9/0  |  提交时间:2020/07/02
Coral skeletons reveal the history of nitrogen cycling in the coastal Great Barrier Reef 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Erler, Dirk V.;  Farid, Hanieh Tohidi;  Glaze, Thomas D.;  Carlson-Perret, Natasha L.;  Lough, Janice M.
收藏  |  浏览/下载:7/0  |  提交时间:2020/05/13
The stoichiometry of soil microbial biomass determines metabolic quotient of nitrogen mineralization 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2020, 15 (3)
作者:  Li, Zhaolei;  Zeng, Zhaoqi;  Tian, Dashuan;  Wang, Jinsong;  Fu, Zheng;  Wang, Bingxue;  Tang, Ze;  Chen, Weinan;  Chen, Han Y. H.;  Wang, Changhui;  Yi, Chuixiang;  Niu, Shuli
收藏  |  浏览/下载:23/0  |  提交时间:2020/07/02
dominant driver  global warming  metabolic quotient  natural ecosystems  nitrogen cycling  stoichiometry of microbial biomass  
Single cell analyses reveal contrasting life strategies of the two main nitrifiers in the ocean 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Kitzinger, Katharina;  Marchant, Hannah K.;  Bristow, Laura A.;  Herbold, Craig W.;  Padilla, Cory C.;  Kidane, Abiel T.;  Littmann, Sten;  Daims, Holger;  Pjevac, Petra;  Stewart, Frank J.;  Wagner, Michael;  Kuypers, Marcel M. M.
收藏  |  浏览/下载:7/0  |  提交时间:2020/05/13
A machine learning examination of hydroxyl radical differences among model simulations for CCMI-1 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (3) : 1341-1361
作者:  Nicely, Julie M.;  Duncan, Bryan N.;  Hanisco, Thomas F.;  Wolfe, Glenn M.;  Salawitch, Ross J.;  Deushi, Makoto;  Haslerud, Amund S.;  Joeckel, Patrick;  Josse, Beatrice;  Kinnison, Douglas E.;  Klekociuk, Andrew;  Manyin, Michael E.;  Marecal, Virginie;  Morgenstern, Olaf;  Murray, Lee T.;  Myhre, Gunnar;  Oman, Luke D.;  Pitari, Giovanni;  Pozzer, Andrea;  Quaglia, Ilaria;  Revell, Laura E.;  Rozanov, Eugene;  Stenke, Andrea;  Stone, Kane;  Strahan, Susan;  Tames, Simone;  Tost, Holger;  Westervelt, Daniel M.;  Zeng, Guang
收藏  |  浏览/下载:21/0  |  提交时间:2020/07/02
Substrate stoichiometry determines nitrogen fixation throughout succession in southern Chinese forests 期刊论文
ECOLOGY LETTERS, 2020, 23 (2) : 336-347
作者:  Zheng, Mianhai;  Chen, Hao;  Li, Dejun;  Luo, Yiqi;  Mo, Jiangming
收藏  |  浏览/下载:6/0  |  提交时间:2020/07/02
Asymbiotic nitrogen fixation  forest succession  nitrogen richness  phosphorus limitation  stoichiometry  substrate