College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4RJ, UK.
Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung, Am Alten Hafen 26, Bremerhaven 27568, Germany.
Nat Commun. 2017 Mar 17;8:14798. doi: 10.1038/ncomms14798.
The history of glaciations on Southern Hemisphere sub-polar islands is unclear. Debate surrounds the extent and timing of the last glacial advance and termination on sub-Antarctic South Georgia in particular. Here, using sea-floor geophysical data and marine sediment cores, we resolve the record of glaciation offshore of South Georgia through the transition from the Last Glacial Maximum to Holocene. We show a sea-bed landform imprint of a shelf-wide last glacial advance and progressive deglaciation. Renewed glacier resurgence in the fjords between c. 15,170 and 13,340 yr ago coincided with a period of cooler, wetter climate known as the Antarctic Cold Reversal, revealing a cryospheric response to an Antarctic climate pattern extending into the Atlantic sector of the Southern Ocean. We conclude that the last glaciation of South Georgia was extensive, and the sensitivity of its glaciers to climate variability during the last termination more significant than implied by previous studies.
南大洋亚南极岛屿上的冰川作用历史尚不清楚。特别是在南乔治亚岛，关于末次冰期前进和结束的范围和时间存在争议。在这里，我们利用海底地球物理数据和海洋沉积物岩芯，通过从末次冰期最大值到全新世的转变，解决了南乔治亚岛近海冰川作用的记录。我们展示了一个海床地貌印记，表明在末次冰期时冰川广泛推进和逐渐消退。大约在 15170 至 13340 年前，峡湾中的冰川再次活跃，与被称为南极冷反转的更凉爽、更湿润的气候时期相吻合，这揭示了对延伸到南大洋大西洋扇区的南极气候模式的冰冻圈响应。我们的结论是，南乔治亚岛的末次冰期是广泛的，其冰川对末次冰期末气候变化的敏感性比以前的研究表明的更为显著。
