Antarctic Ice Sheet dynamics over the past 4 million years (ICEBERGS)

我们需要对气候系统的临界点有更精确的了解，以更好地评估未来全球变化的速度和幅度。在这里，南极冰盖的作用是至关重要的，因为它的融化可能会使全球海平面上升60米。过去两个世纪的仪器气候记录缺乏气候模型预测中经常使用的非线性阈值行为;然而，地质记录表明，地球系统的大规模且往往不可逆转的变化发生在过去的临界点。我希望研究南极洲在过去400万年中通过这些关键临界点的动态和冰量损失历史，当时温度、大气二氧化碳或全球海平面都高于今天。这些时间是末次间冰期，海洋同位素阶段11，中更新世过渡和上新世中期温暖期。我将集中讨论冰山，这是一个巨大的未知数，尽管它们贡献了南极总冰量损失的一半。最近从斯科舍海的冰山巷及其周围回收的IODP核心材料将成为地理重点。这是南极冰山经过并最终融化的中心路径，在海洋沉积物中积累了冰山漂流碎片。这一工作将得到南极关键地点的其他海洋综合开发方案和臭氧消耗方案场址的补充。如此大规模的环南极工作，包括确定冰山来源的地球化学方法，以前从未做过，也没有基于人工智能的方法来科普大量的数据。补充研究应进行可比较的粒度分析，产生尘埃指标以建立轨道年表，并从地球化学角度确定南极大陆冰山的来源。ICEBERGS项目有可能提供对过去冰山排放历史的时间和动态的基本见解，并更好地评估相关的全球海平面上升。这是第一次长期的南极冰量损失重建，也可以为气候模型校准提供急需的数据，从而影响一些科学领域。

We need a much more refined understanding of tipping points in the climate system to better assess the pace and magnitude of future global changes. Here, the role of the Antarctic Ice Sheet is crucial and heavily debated since its melting could rise global sea levels by up to 60 m. Instrumental climate records of the last two centuries lack the non-linear, threshold behavior often used in climate model projections; however, geological records indicate that large-scale and often irreversible shifts in the Earth system took place at such past tipping points. I wish to study the dynamics and ice-mass loss history of Antarctica through such critical tipping points over the past 4 million years, when either temperature, atmospheric carbon dioxide or global sea level were higher than today. Such times are the Last Interglacial, Marine Isotopic Stage 11, the Mid-Pleistocene Transition and the Mid-Pliocene Warm Period. I will focus on icebergs which are the big unknown although they contribute half of the total Antarctic ice-mass loss. Recently recovered IODP core material from and around Scotia Sea’s Iceberg Alley will be the geographic focus. This is the central pathway where Antarctic icebergs route through and finally melt down, accumulating iceberg-rafted debris in ocean sediment. This work will be complemented by further IODP and ODP sites from Antarctic key locations. Such a large-scale, circum-Antarctic work, which includes determining the iceberg source geochemically, has never been done before, nor has the Artificial Intelligence based method intended to utilize to cope with the vast amount of data, ever been implemented. Complementary studies shall conduct comparable grain-size analysis, generate dust indicators to establish the orbital-based chronology, and determine the source of icebergs on the Antarctic continent geochemically. Project ICEBERGS has the potential to provide fundamental insight into the timing and dynamics of past iceberg discharge history and to better assess associated global sea-level rise. This first, long-term Antarctic ice-mass loss reconstruction can also deliver much needed data for climate model calibration and hence impact a number of scientific fields.