Deglaciation of northwestern Greenland during Marine Isotope Stage 11
Deglaciation of northwestern Greenland during Marine Isotope Stage 11
复制标题
DOI：
10.1126/science.ade4248
复制
发表时间：
2023-07
期刊：
影响因子：
56.9
通讯作者：
A. Christ;T. Rittenour;P. Bierman;B. Keisling;P. Knutz;T. Thomsen;Nynke Keulen;J. Fosdick;S. Hemming;J. Tison;P. Blard;J. Steffensen;M. Caffee;L. Corbett;D. Dahl-Jensen;D. Dethier;A. Hidy;N. Perdrial;D. Peteet;E. Steig;E. Thomas
中科院分区：
文献类型：
--
作者：
A. Christ;T. Rittenour;P. Bierman;B. Keisling;P. Knutz;T. Thomsen;Nynke Keulen;J. Fosdick;S. Hemming;J. Tison;P. Blard;J. Steffensen;M. Caffee;L. Corbett;D. Dahl-Jensen;D. Dethier;A. Hidy;N. Perdrial;D. Peteet;E. Steig;E. Thomas
过去的间冰期气候与较小的冰盖提供了类似的冰盖对未来变暖的反应和对海平面上升的贡献;然而，来自以前无冰区的日期明确的地质记录是罕见的。在这里，我们报告说，冰下沉积物从营世纪冰芯保存直接证据表明，格陵兰岛西北部是冰免费的海洋同位素阶段（MIS）11间冰期。发光测年表明，冰盖下的沉积物是41.6 ± 3.8万年前在无冰环境中由流水沉积的。物源分析和宇宙成因核素数据和计算表明，沉积物是由当地物质改造而成的，在沉积前不到1.6万年就暴露在地表。冰盖模拟表明，世纪营地的无冰条件需要格陵兰冰盖至少1.4米的海平面当量。对格陵兰西北部世纪营冰芯的冰下沉积物进行的测量表明，在大约40万年前发生的间冰期期间，该地点没有冰。克里斯特等人使用发光测年和宇宙成因核素数据表明，沉积物是在不到16，000年前暴露在阳光下后在无冰条件下沉积的。该位置没有冰意味着格陵兰冰盖必须贡献超过1.4米的海平面，相当于高海平面，当时全球平均气温与我们即将经历的人类造成的气候变暖相似。-H. 40万年前，格陵兰冰盖的融化使海平面上升了至少1.4米。
Past interglacial climates with smaller ice sheets offer analogs for ice sheet response to future warming and contributions to sea level rise; however, well-dated geologic records from formerly ice-free areas are rare. Here we report that subglacial sediment from the Camp Century ice core preserves direct evidence that northwestern Greenland was ice free during the Marine Isotope Stage (MIS) 11 interglacial. Luminescence dating shows that sediment just beneath the ice sheet was deposited by flowing water in an ice-free environment 416 ± 38 thousand years ago. Provenance analyses and cosmogenic nuclide data and calculations suggest the sediment was reworked from local materials and exposed at the surface <16 thousand years before deposition. Ice sheet modeling indicates that ice-free conditions at Camp Century require at least 1.4 meters of sea level equivalent contribution from the Greenland Ice Sheet. Description Editor’s summary Measurements made on subglacial sediment from the Camp Century ice core in northwestern Greenland show that the location was ice free during the interglacial that occurred around 400,000 years ago. Christ et al. used luminescence dating and cosmogenic nuclide data to show that the sediment was deposited under ice-free conditions after having been exposed at the surface to sunlight fewer than 16,000 years earlier. The absence of ice at that location means that the Greenland Ice Sheet must have contributed more than 1.4 meters of sea-level equivalent to the high sea-level stand, when the average global air temperature was similar to what we will soon experience because of human-caused climate warming. —H. Jesse Smith Melting of the Greenland Ice Sheet raised sea level by at least 1.4 meters 400,000 years ago.