Glacial ice-sheet dynamics and retreat deduced from southeastern Weddell Sea sediment (LAMINAE)

作为研究束之谜(在不同尺度上重建冰盖动力学)的一部分，Llamae项目的关键目标是提供对南极洲威德尔海东南部冰盖动力学的详细了解。在最后一次冰川盛期(LGM)期间保存了至少五千年变化序列的十个现有沉淀点将用多代理方法进行研究。首先，南极冰盖在末次盛冰期结束时的最后退缩日期将是14C。这一结果将有助于限制南极西部和东部冰盖最初海平面上升的时间，包括潜在的不同步。其次，我们将从新的叶片识别和波形计数方法中建立浮动年表。因此，将有可能以前所未有的分辨率研究冰盖动力学，包括十年-百年尺度太阳周期在气候变化中的作用，以及穿透海洋同位素第三阶段的地点的南极同位素极大值的探测。第三，结合绝对年代学和浮动年代学，我们将在富含生物扰动、冰筏碎片或火山灰层的岩心剖面中定义标志层，以便在地点之间和EDML冰芯之间进行对比。这将把我们的结果放在更大范围的视角中，并允许大气和海洋对气候变化的反应同步。

As part of research bundle RIDDLE (Reconstructing ice-sheet dynamics on different scales), the key goal of project LAMINAE is to provide detailed insight into glacial ice sheet dynamics in the southeastern Weddell Sea section of Antarctica. Ten existing sediment sites that preserved at least five millennia of varved sequences during the last glacial maximum (LGM) will be studied with a multi-proxy approach. First, the final retreat of the Antarctic Ice Sheet at the end of the LGM will be dated with 14C. The results will help to confine the timing of the initial sea-level rise for both the West and East Antarctic Ice Sheets, including potential asynchronies. Second, we will establish floating chronologies from new methods for laminae recognition and varve counting. Thereby, it will be possible to study glacial ice sheet dynamics at unprecedented resolution, including the role of decadal-centennial scale solar cycles in climate change, and the detection of Antarctic Isotopic Maxima in sites penetrating Marine Isotopic Stage 3. Third, with the combination of absolute and floating chronologies, we will define marker horizons in core sections that are rich in bioturbation, ice-rafted debris, or ash layers, for correlation between the sites and to the EDML ice core. This will put our results into a larger-scale perspective and allow for synchronization of the atmospheric and oceanic response to climate change.