Abstract The Lambert Glacier-Amery Ice Shelf system (LGAISS) is the largest outlet glacier system in East Antarctica but its response to past climate variability is poorly constrained. In this study, we explore its dynamics over the last ∼520 thousand years using new high-resolution sedimentary records retrieved off Prydz Bay. Episodic occurrences of iceberg rafted debris indicate a dynamic ice sheet throughout this interval, while changes in clay mineral compositions provide detailed evidence on the waxing and waning of the LGAISS. Our data indicate that advance and retreat of the LGAISS was sensitive to oceanic forcing, but also responded to local summer insolation when insolation peaks combined with interglacial sea level high stands. Subglacial bed topography may have played an additional role in modulating the LGAISS behaviour, which could explain sectoral differences in the response of the East Antarctic Ice Sheet to climate change. Overall, our records indicate that the LGAISS advanced more extensively during previous late Quaternary glacial periods than during Marine Isotope Stages 2 and 4. Furthermore, the LGAISS retreated more significantly than present during Marine Isotope Stage 13, and only moderately during Marine Isotope Stage 7, which suggests that the duration of warm climatic states could be a key factor affecting the dynamics of the East Antarctic Ice Sheet.

中文翻译：

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南极洲东部兰伯特冰川-阿默里冰架系统的晚第四纪动力学

摘要 兰伯特冰川-阿默里冰架系统 (LGAISS) 是南极洲东部最大的出口冰川系统，但其对过去气候变率的响应却很少受到限制。在这项研究中，我们使用在普里兹湾 (Prydz Bay) 检索到的新的高分辨率沉积记录探索了过去 52 万年的动态。冰山漂流碎片的偶发事件表明整个区间内有一个动态冰盖，而粘土矿物成分的变化提供了关于 LGAISS 增减的详细证据。我们的数据表明，LGAISS的进退对海洋强迫敏感，但当日照高峰与间冰期海平面高位相结合时，也对当地夏季日照做出了反应。冰下床地形可能在调节 LGAISS 行为方面发挥了额外的作用，这可以解释南极东部冰盖对气候变化反应的部门差异。总体而言，我们的记录表明 LGAISS 在之前的第四纪晚期冰期比在海洋同位素第 2 和第 4 阶段更广泛地推进。此外，LGAISS 在海洋同位素第 13 阶段比现在更显着，并且在海洋同位素第 7 阶段仅适度后退，这表明温暖气候状态的持续时间可能是影响南极东部冰盖动态的关键因素。