Using Radiochemical Data from Collapsed Ice Shelf Sediments to Understand the Nature and Timing of the Benthic Response to High-Latitude Climate Change

知识价值：PI要求支持分析先前从前Larsen B和Larsen A冰架下收集的多芯和超大芯沉积物。这些独特的核心将使PI能够对南极半岛东部冰架崩塌的底栖生物反应进行时间整合，从冰架崩塌后的5年到崩塌后的170年。高纬度地区对气候变化的反应比地球上其他地区更快，冰架的消失是气候变暖的一个主要表现。PI将调查新形成的底栖环境和相关的生态系统，这些环境是由于新鲜浮游生物物质重新进入沉积物-水界面而产生的。该提案将使用一种新的地球化学技术，该技术基于自然产生的14C，可用于评估前拉森a和B冰架下沉积物中最近产生的有机碳的分布和库存。PI将结合14C测量和210Pb分析来评估沉积活性有机物的周转时间。通过比较冰架崩塌/退缩后不同地点间活性有机物的分布和存量以及生物扰动强度随时间的变化，可以评估底栖生物对冰架崩塌响应的性质和时间。更广泛的影响：这项研究将提供重要的信息，描述冰架崩塌后海底发生的变化。这项研究将支持一名研究生的研究项目。这个项目汇集了来自欧洲共同体和LARISSA项目的研究人员。

Intellectual Merit: The PI requests support to analyze sediments from multi-cores and mega-cores previously collected from beneath the former Larsen B and Larsen A ice shelves. These unique cores will allow the PI to develop a time-integrated understanding of the benthic response to ice shelf collapse off the East Antarctic Peninsula over time periods as short as 5 years following ice shelf collapse up to 170 years after collapse. High latitudes are responding to climate change more rapidly than the rest of the planet and the disappearance of ice shelves are a key manifestation of climate warming. The PI will investigate the newly created benthic environments and associated ecosystems that have resulted from the re-initiation of fresh planktonic material to the sediment-water interface. This proposal will use a new geochemical technique, based on naturally occurring 14C that can be used to assess the distribution and inventory of recently produced organic carbon accumulating in the sediments beneath the former Larsen A and B ice shelves. The PI will couple 14C measurements with 210Pb analyses to assess turnover times for sedimentary labile organic matter. By comparing the distributions and inventories of labile organic matter as well as the bioturbation intensities among different locations as a function of time following ice shelf collapse/retreat, the nature and timing of the benthic response to ice shelf collapse can be assessed. Broader impacts: This study will provide important information characterizing changes occurring on the seafloor after the collapse of ice shelves. This research will support the research project of a graduate student. This project brings together researchers from both the European community and the LARISSA Project.