期刊
GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS
卷 23, 期 9, 页码 -出版社
AMER GEOPHYSICAL UNION
DOI: 10.1029/2022GC010470
关键词
Antarctica; WAIS instability; ocean forcing; iceberg-rafted debris; clay minerals; Sr-Nd isotopes; Pleistocene
资金
- Impact and Response of Antarctic Seas to Climate Change [IRASCC2020-2022-01-03-02, IRASCC2020-2022-01-02-03]
- Basic Scientific Fund for National Public Research Institutes of China [2019Q09, 2019S04, 2017Y07]
- National Natural Science Foundation of China [41976080, 42076232]
- Strategic Priority Research Program of the Chinese Academy of Sciences [XDB42000000]
- Taishan Scholars Project Funding [ts20190963]
- Natural Environment Research Council independent research fellowship [NE/T011440/1]
The study provides evidence on the instability of the West Antarctic Ice Sheet throughout the Pleistocene glacial/interglacial cycles and suggests a temporal link with a strengthened Antarctic Circumpolar Current, enhanced deepwater ventilation, and poleward-shifted southern westerly winds. The insights into the role of ocean-atmosphere forcing on the past behavior of the West Antarctic Ice Sheet may enhance our understanding of future changes in this region.
Evidence on West Antarctic Ice Sheet (WAIS) instability through Pleistocene glacial/interglacial cycles can provide fundamental constraints on interactions between the climate system and cryosphere. To explore such ice sheet-ocean-climate processes on orbital timescales over the last similar to 770 ka, we provide continuous records of iceberg-rafted debris (IRD) content and clay mineralogy, supported by detrital Sr-Nd isotopes from the pronounced IRD peaks, in gravity core ANT34/A2-10 from the Amundsen abyssal plain. The IRD record reveals interglacial WAIS instability since similar to 770 ka, while comparison to the clay mineralogy record and published records of regional oceanic and atmospheric forcing suggests a temporal link with a strengthened Antarctic Circumpolar Current, enhanced deepwater ventilation, and poleward-shifted southern westerly winds. In addition, the Sr-Nd isotope signature of the detrital sediments indicates a shift in provenance around Marine Isotope Stage (MIS) 16, potentially linked to regional oceanic circulation changes. We suggest that an expanded Ross Gyre was important for controlling iceberg trajectories and sediment transport to the site before MIS 16, whereas modern-like iceberg trajectories were established after MIS 16, probably related to a poleward shift of the Amundsen Sea Low after the end of the Mid-Pleistocene Transition. This reorganization of the ocean and atmospheric circulation was followed by an interval of enhanced WAIS variability during MIS 15 to 13, which was linked to strong orbital and ocean forcing. These insights into the role of ocean-atmosphere forcing on the past behavior of the WAIS may improve our framework for understanding future changes in this region.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据