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

来自地震记录和钻探数据的罗斯海和阿蒙森海海湾之间的西南极冰盖动态（IODP 探险 379 和 374）

• 批准号: 427200564
• 负责人: Professor Dr. Karsten Gohl
• 金额: --
• 依托单位: Sektion Geophysik
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/427200564?language=en
• 关键词: West; Antarctic; Ice; Sheet; dynamics

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.

海底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升高的时期。由于目前观察到温暖的环极深水的入侵以及正在进行的冰下、海洋驱动的融化过程，WAIS 的阿蒙森海区域尤其脆弱。这些观测结果以及解决古冰盖限制以更好地预测未来海平面的必要性，使罗斯海海湾和阿蒙森海海湾成为连续两次 IODP 探险的目的地 374（2018 年初）和 379（2019 年初）。这两个区域通过连续的地震横断面连接起来，该横断面将补充 2019 年初俄罗斯探险期间收集的大陆隆起的额外地震剖面。这些地震剖面将在阿蒙森海和罗斯海的层序地层之间建立差异和详细的比较。在与 IODP 探险队和俄罗斯合作伙伴的科学团队的合作中，我们计划分析新的地震数据，将其与现有的地震剖面相结合，并对两个海湾之间区域的地震地层序列、单元和层位进行彻底而详细的研究。地震网络将通过仔细的地震与岩心测井集成连接到 IODP 374 和 379 钻探场地，该集成将使用钻探岩心记录、物理特性数据和井下测井数据进行。生成的合成地震图将用于与这些地点的地震剖面记录进行比较。第一个工作阶段的目标是建立阿蒙森海和罗斯海区域的跨区域地层年龄和沉积成分模型。这将包括开发冰期前和冰期主导的沉积物运输/沉积模型，以便破译和理解从温室到冰库环境的过渡阶段。在第二个综合阶段，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。沉积模型将显示阿蒙森海和罗斯海区域之间 WAIS 过去的冰川流出特征是否以及如何变化。