West Antarctic Ice Sheet dynamics between Ross Sea and Amundsen Sea embayments from seismic records and drill data (IODP Expeditions 379 and 374)

海底的西南极冰盖被怀疑对气候变化高度敏感，特别是在全球大气温度上升的时期。WAIS的阿蒙森海区尤其脆弱，因为目前观察到温暖的绕极深水入侵，以及正在进行的冰下海洋驱动的融化过程。这些观测结果，以及为了更好地预测未来海平面而处理古冰盖制约因素的必要性，使罗斯湾和阿蒙森海湾成为IODP连续两次考察的目的地：374次(2018年初)和379次(2019年初)。这两个地区通过一个连续的地震横断面连接在一起，该横断面将由2019年初俄罗斯探险队收集的大陆隆起上的额外地震剖面补充。地震剖面将在阿蒙森海和罗斯海的层序地层之间建立区别和详细的对比。在与IODP考察队和俄罗斯合作伙伴的科学小组的合作下，我们计划分析新的地震数据，将它们与先前存在的地震剖面结合起来，并对两个海湾之间地区的地震地层序列、单位和层位进行彻底和详细的研究。地震网络将通过使用钻芯记录、物性数据和井下测井数据进行仔细的地震与岩心-测井综合，与IODP 374和379个钻探地点相连。生成的合成地震记录将被用来与这些地点的地震剖面记录进行比较。阿蒙森海和罗斯海地区的跨区域地层年龄和沉积成分模式是这一第一阶段工作的目标。这将包括开发冰前和冰川主导的沉积物运输/沉积模型，以便破译和了解从温室环境到冰库环境的过渡阶段。在第二个合成阶段，冰川主导的沉积过程将被转化为描述阿蒙森海和罗斯海地区WAIS的流动动力学模式。沉积模型将显示过去WAIS的冰川流出特征是否以及如何在阿蒙森海和罗斯海区段之间发生变化。

The submarine-based West Antarctic Ice Sheet is suspected to be highly sensitive to climate changes, in particular to in periods of increasing global atmospheric temperatures. The Amundsen Sea sector of the WAIS is in particular vulnerable, because of currently observed incursions of warm Circumpolar Deep Water and ongoing subglacial, ocean-driven melt processes. These observations and the necessity to address paleo-ice sheet constraints for better future sea-level projections have made both the Ross Sea Embayment and the Amundsen Sea Embayment destinations of the two consecutive IODP Expeditions 374 (early 2018) and 379 (early 2019). Both regions are connected via a continuous seismic transect that will be supplemented with additional seismic profiles on the continental rise to be collected during a Russian expedition in early 2019. The seismic profiles will establish a differential and detailed comparison between the sequence stratigraphies of the Amundsen Sea and Ross Sea. In a collaborative effort with the Science Teams of both IODP expeditions and the Russian partners, we plan to analyse the new seismic data, integrate them with pre-existing seismic profiles and perform a thorough and detailed study on the seismic-stratigraphic sequences, units and horizons across the region between the two embayments. The seismic network will be linked to the IODP 374 and 379 drill sites via a careful seismic to core-log integration which will be conducted using the drill core records, physical property data and downhole logging data. Generated synthetic seismograms will be used to compare with seismic profile records at these sites. A trans-regional stratigraphic age and sedimentary compositional model across the Amundsen Sea and Ross Sea sectors is the aim of this first work phase. This will include the development of pre-glacial and glacially dominated sediment transport/deposition models in order to decipher and understand the transitional change-over phase from the greenhouse to the icehouse environment. In the second synthesis phase, the glacially dominated sedimentation processes will be translated to describe flow dynamical patterns of the WAIS in the Amundsen Sea and Ross Sea regions. The sedimentary model will show if and how the past glacial outflow characteristics of the WAIS has changed between Amundsen Sea and Ross Sea sectors.