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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.


  
Molecular hydrogen in minerals as a clue to interpret partial derivative D variations in the mantle 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Moine, B. N.;  Bolfan-Casanova, N.;  Radu, I. B.;  Ionov, D. A.;  Costin, G.;  Korsakov, A., V;  Golovin, A., V;  Oleinikov, O. B.;  Deloule, E.;  Cottin, J. Y.
收藏  |  浏览/下载：12/0  |  提交时间：2020/07/21
Breaking Earth's shell into a global plate network 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Tang, C. A.;  Webb, A. A. G.;  Moore, W. B.;  Wang, Y. Y.;  Ma, T. H.;  Chen, T. T.
收藏  |  浏览/下载：10/0  |  提交时间：2020/07/21
Large-scale mass wasting in the western Indian Ocean constrains onset of East African rifting 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Maselli, Vittorio;  Iacopini, David;  Ebinger, Cynthia J.;  Tewari, Sugandha;  de Haas, Henk;  Wade, Bridget S.;  Pearson, Paul N.;  Francis, Malcom;  van Vliet, Arjan;  Richards, Bill;  Kroon, Dick
收藏  |  浏览/下载：8/0  |  提交时间：2020/07/14
Methylmercury produced in upper oceans accumulates in deep Mariana Trench fauna 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Sun, Ruoyu;  Yuan, Jingjing;  Sonke, Jeroen E.;  Zhang, Yanxu;  Zhang, Tong;  Zheng, Wang;  Chen, Shun;  Meng, Mei;  Chen, Jiubin;  Liu, Yi;  Peng, Xiaotong;  Liu, Congqiang
收藏  |  浏览/下载：10/0  |  提交时间：2020/07/09
Limited and localized magmatism in the Central Atlantic Magmatic Province 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Marzen, R. E.;  Shillington, D. J.;  Lizarralde, D.;  Knapp, J. H.;  Heffner, D. M.;  Davis, J. K.;  Harder, S. H.
收藏  |  浏览/下载：9/0  |  提交时间：2020/07/09
Rapid geomagnetic changes inferred from Earth observations and numerical simulations 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Davies, Christopher J.;  Constable, Catherine G.
收藏  |  浏览/下载：7/0  |  提交时间：2020/07/09
Low thermal conductivity of iron-silicon alloys at Earth's core conditions with implications for the geodynamo 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Hsieh, Wen-Pin;  Goncharov, Alexander F.;  Labrosse, Stephane;  Holtgrewe, Nicholas;  Lobanov, Sergey S.;  Chuvashova, Irina;  Deschamps, Frederic;  Lin, Jung-Fu
收藏  |  浏览/下载：12/0  |  提交时间：2020/07/06
Increasing trends in regional heatwaves 期刊论文
NATURE COMMUNICATIONS, 2020, 11 (1)
作者:  Perkins-Kirkpatrick, S. E.;  Lewis, S. C.
收藏  |  浏览/下载：2/0  |  提交时间：2020/07/06
A remnant planetary core in the hot-Neptune desert 期刊论文
NATURE, 2020, 583 (7814) : 39-+
作者:  David J. Armstrong;  Thé;  o A. Lopez;  Vardan Adibekyan;  Richard A. Booth;  Edward M. Bryant;  Karen A. Collins;  Magali Deleuil;  Alexandre Emsenhuber;  Chelsea X. Huang;  George W. King;  Jorge Lillo-Box;  Jack J. Lissauer;  Elisabeth Matthews;  Olivier Mousis;  Louise D. Nielsen;  Hugh Osborn;  Jon Otegi;  Nuno C. Santos;  Sé;  rgio G. Sousa;  Keivan G. Stassun;  Dimitri Veras;  Carl Ziegler;  Jack S. Acton;  Jose M. Almenara;  David R. Anderson;  David Barrado;  Susana C. C. Barros;  Daniel Bayliss;  Claudia Belardi;  Francois Bouchy;  Cé;  sar Briceñ;  o;  Matteo Brogi;  David J. A. Brown;  Matthew R. Burleigh;  Sarah L. Casewell;  Alexander Chaushev;  David R. Ciardi;  Kevin I. Collins;  Knicole D. Coló;  n;  Benjamin F. Cooke;  Ian J. M. Crossfield;  Rodrigo F. Dí;  az;  Elisa Delgado Mena;  Olivier D. S. Demangeon;  Caroline Dorn;  Xavier Dumusque;  Philipp Eigmü;  ller;  Michael Fausnaugh;  Pedro Figueira;  Tianjun Gan;  Siddharth Gandhi;  Samuel Gill;  Erica J. Gonzales;  Michael R. Goad;  Maximilian N. Gü;  nther;  Ravit Helled;  Saeed Hojjatpanah;  Steve B. Howell;  James Jackman;  James S. Jenkins;  Jon M. Jenkins;  Eric L. N. Jensen;  Grant M. Kennedy;  David W. Latham;  Nicholas Law;  Monika Lendl;  Michael Lozovsky;  Andrew W. Mann;  Maximiliano Moyano;  James McCormac;  Farzana Meru;  Christoph Mordasini;  Ares Osborn;  Don Pollacco;  Didier Queloz;  Liam Raynard;  George R. Ricker;  Pamela Rowden;  Alexandre Santerne;  Joshua E. Schlieder;  Sara Seager;  Lizhou Sha;  Thiam-Guan Tan;  Rosanna H. Tilbrook;  Eric Ting;  Sté;  phane Udry;  Roland Vanderspek;  Christopher A. Watson;  Richard G. West;  Paul A. Wilson;  Joshua N. Winn;  Peter Wheatley;  Jesus Noel Villasenor;  Jose I. Vines;  Zhuchang Zhan
收藏  |  浏览/下载：17/0  |  提交时间：2020/07/06

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune '  desert'  (1,2)(a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b(3), which is thought to have an unusually massive core, and recent discoveries such as LTT9779b(4)and NGTS-4b(5), on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune'  s but an anomalously large mass of39.1-2.6+2.7Earth masses and a density of5.2-0.8+0.7grams per cubic centimetre, similar to Earth'  s. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than3.9-0.9+0.8 per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation(6). Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.


Observations of TOI-849b reveal a radius smaller than Neptune'  s but a large mass of about 40 Earth masses, indicating that the planet is the remnant core of a gas giant.