Jamieson Stewart S R, Ross Neil, Paxman Guy J G, Clubb Fiona J, Young Duncan A, Yan Shuai, Greenbaum Jamin, Blankenship Donald D, Siegert Martin J
Department of Geography, Durham University, Durham, DH1 3LE, UK.
School of Geography, Politics and Sociology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK.
Nat Commun. 2023 Oct 24;14(1):6507. doi: 10.1038/s41467-023-42152-2.
The East Antarctic Ice Sheet (EAIS) has its origins ca. 34 million years ago. Since then, the impact of climate change and past fluctuations in the EAIS margin has been reflected in periods of extensive vs. restricted ice cover and the modification of much of the Antarctic landscape. Resolving processes of landscape evolution is therefore critical for establishing ice sheet history, but it is rare to find unmodified landscapes that record past ice conditions. Here, we discover an extensive relic pre-glacial landscape preserved beneath the central EAIS despite millions of years of ice cover. The landscape was formed by rivers prior to ice sheet build-up but later modified by local glaciation before being dissected by outlet glaciers at the margin of a restricted ice sheet. Preservation of the relic surfaces indicates an absence of significant warm-based ice throughout their history, suggesting any transitions between restricted and expanded ice were rapid.
东南极冰盖（EAIS）起源于约3400万年前。从那时起，气候变化以及EAIS边缘过去的波动影响，已反映在冰盖广泛覆盖与受限覆盖的时期，以及南极大部分地貌的改变中。因此，解析地貌演化过程对于确定冰盖历史至关重要，但很难找到记录过去冰况的未被改变的地貌。在这里，我们发现尽管有数百万年的冰盖覆盖，在EAIS中部之下仍保存着一片广阔的残留冰川前地貌。该地貌在冰盖形成之前由河流塑造，但后来在局部冰川作用下发生了改变，之后在受限冰盖边缘被流出冰川切割。残留表面的保存表明在其整个历史中不存在显著的暖基冰，这表明冰盖受限与扩张之间的任何转变都是迅速的。
