Since the Last Glacial Maximum ∼20,000 years ago, the Antarctic Ice Sheet has undergone extensive changes, resulting in a much smaller present-day configuration. Improving our understanding of basic physical processes that played important roles during that retreat is critical to providing more robust model projections of future retreat and sea-level rise. Here, a limited-area nested ice sheet model was applied to the last deglacial retreat of the West Antarctic Ice Sheet in the Amundsen Sea Embayment (ASE), at 5 km resolution. The ice sheet response to climate and sea-level forcing was examined at two sites along the flowlines of Pine Island Glacier and Pope Glacier, close to the Hudson Mountains and Mount Murphy respectively, and the simulated responses compared with ice sheet thinning histories derived from glacial-geological data. The sensitivity of results to selected model parameters was also assessed. The model simulations predict a broadly similar response to ocean forcing in both the central and eastern ASE, with an initial rapid phase of thinning followed by a slower phase to the modern configuration. Although there is a mismatch of up to 5,000 years between the timing of simulated and observed thinning, the modeling suggests that the upstream geological records of ice surface elevation change reflect a response to retreat near the grounding line. The model-data mismatch could potentially be improved by accounting for regional variations in mantle viscosity, sea-surface heights and basal sliding properties across the continental shelf.

中文翻译：

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南极阿蒙森海区末次冰期以来冰盖变化的冰​​川地质证据和模型模拟比较

自 20,000 年前的末次盛冰期以来，南极冰盖经历了广泛的变化，导致今天的构造要小得多。提高我们对在那次撤退期间发挥重要作用的基本物理过程的理解对于提供更可靠的未来撤退和海平面上升模型预测至关重要。在这里，有限区域嵌套冰盖模型应用于阿蒙森海海湾 (ASE) 中南极西部冰盖的最后一次冰消退，分辨率为 5 公里。在分别靠近哈德逊山脉和墨菲山的松岛冰川和教皇冰川流线的两个地点检查了冰盖对气候和海平面强迫的响应，并将模拟响应与来自冰川的冰盖变薄历史进行比较- 地质数据。还评估了结果对选定模型参数的敏感性。模型模拟预测，ASE 中部和东部对海洋强迫的响应大致相似，初始快速变薄阶段，然后是现代构造的较慢阶段。尽管模拟和观察到的变薄时间之间存在长达 5,000 年的不匹配，但建模表明，冰面海拔变化的上游地质记录反映了接地线附近退缩的响应。通过考虑跨大陆架的地幔粘度、海面高度和基底滑动特性的区域变化，模型数据不匹配可能会得到改善。模型模拟预测，ASE 中部和东部对海洋强迫的响应大致相似，初始快速变薄阶段，然后是现代构造的较慢阶段。尽管模拟和观察到的变薄时间之间存在长达 5,000 年的不匹配，但建模表明，冰面海拔变化的上游地质记录反映了接地线附近退缩的响应。通过考虑跨大陆架的地幔粘度、海面高度和基底滑动特性的区域变化，模型数据不匹配可能会得到改善。模型模拟预测，ASE 中部和东部对海洋强迫的响应大致相似，初始快速变薄阶段，然后是现代构造的较慢阶段。尽管模拟和观察到的变薄时间之间存在长达 5,000 年的不匹配，但建模表明，冰面海拔变化的上游地质记录反映了接地线附近退缩的响应。通过考虑跨大陆架的地幔粘度、海面高度和基底滑动特性的区域变化，模型数据不匹配可能会得到改善。在模拟和观察到的变薄时间之间 000 年，该模型表明冰面海拔变化的上游地质记录反映了接地线附近的退缩反应。通过考虑跨大陆架的地幔粘度、海面高度和基底滑动特性的区域变化，模型数据不匹配可能会得到改善。在模拟和观察到的变薄时间之间 000 年，该模型表明冰面海拔变化的上游地质记录反映了接地线附近的退缩反应。通过考虑跨大陆架的地幔粘度、海面高度和基底滑动特性的区域变化，模型数据不匹配可能会得到改善。