Collaborative Research: Spatiotemporal observations of the demise of an ice sheet: Paleo perspectives from Baffin Bay, West Greenland.

合作研究：冰盖消亡的时空观察：西格陵兰巴芬湾的古视角。

• 批准号: 2300114
• 负责人: Brendan Reilly
• 金额: $ 21.44万
• 依托单位: Columbia University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-10-01 至 2025-09-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2300114&HistoricalAwards=false
• 关键词: Collaborative; Research; Spatiotemporal; observations; demise

The Greenland Ice Sheet (GIS) is shrinking today in response to the warming atmosphere and ocean. The GIS holds enough freshwater to raise sea level by 7.4 meters (24 feet) if it melted completely. Thus, understanding how it responds to warming is important. This project will investigate GIS vulnerability by studying how the GIS responded to climate warming in the past. At the end of the last ice age, about 20,000 years ago, the western GIS margin extended farther into Baffin Bay, hundreds of kilometers west of its present position. By 10,000 years ago, the ice margin had largely retreated to within the current coastline. It is unclear if a warming atmosphere, a warming ocean, or some combination of the two is responsible for the retreat. Sediments studied along the West Greenland margin as part of this project will establish regional variations in the timing, magnitude, and rate of GIS retreat during the deglaciation. The relative timing of GIS changes and ocean warming, recorded in the same sediments, will improve our understanding of the behavior of large ice sheets in the past and future. The project broader impacts include support for a postdoctoral researcher, three graduate students, and undergraduate researchers. In addition, the project will support production of an outreach film based on the proposed research expedition. The project also will facilitate development of an upper-level undergraduate course focused on the deglaciation. To accomplish this goal, an oceanographic expedition will study four West Greenland trough mouth fan systems (where the GIS deposited large volumes of sediment when it extended offshore) using seafloor and sub-seafloor imaging techniques and by collecting sediment cores spanning the end of the last ice age to present. Biological, magnetic, geochemical, and physical properties from the sediment records will be used to test the primary hypothesis; that increasing ocean temperature at the base of marine terminating glaciers is a major driver of ice-sheet instability. The project will establish: 1) the timing and extent of warm Atlantic water incursion along the west Greenland margin; 2) the phasing of ice margin retreat and ocean change; and 3) the influence of regional geology, geomorphology, and ice dynamics on ice-margin retreat. Early career leadership (supported by senior mentors) is at the heart of this project with three US-based assistant professors and one post-doctoral researcher directing shipboard operations and spearheading the post-expedition science. Half of the sea-going science party will be graduate and undergraduate students. Acquisition of the first US-based sediment cores from Baffin Bay and archival of the cores and data in US facilities and databases will provide diverse high-latitude research opportunities to the NSF community, ensuring the continuing legacy of this project.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

今天，格陵兰冰盖（GIS）正在响应温暖的气氛和海洋，今天正在收缩。如果GIS完全融化，GIS拥有足够的淡水以将海平面提高7.4米（24英尺）。因此，了解它对变暖的反应很重要。该项目将通过研究GIS过去对气候变暖的反应来调查GIS脆弱性。在大约20，000年前的最后一个冰河时代结束时，西GIS的边缘延伸到Baffin湾，位于其目前的位置以西数百公里。到10，000年前，冰的利润在很大程度上撤退到了当前的海岸线内。目前尚不清楚温暖的气氛，温暖的海洋或两者的某种组合是造成撤退的原因。作为该项目的一部分，沿西格陵兰边缘研究的沉积物将在脱胶过程中建立GIS撤退的时机，幅度和速率的区域变化。 GIS变化和海洋变暖的相对时机记录在同一沉积物中，将提高我们对过去和未来大型冰盖行为的理解。该项目更广泛的影响包括对博士后研究人员，三名研究生和本科研究人员的支持。此外，该项目将根据拟议的研究探险支持制作外展电影。该项目还将促进开发针对脱气的高级本科课程。 为了实现这一目标，一场海洋探险将使用海底和层状成像技术，并通过收集跨越最后一个冰河时代的末端的沉积物岩心来研究四个西格陵兰口嘴扇形系统（GIS在延长海上时沉积了大量沉积物）。沉积物记录中的生物学，磁，地球化学和物理特性将用于检验主要假设。海洋底部终止冰川的海洋温度升高是冰原不稳定性的主要驱动力。该项目将建立：1）西格陵兰边缘沿线温暖的大西洋水分的时机和程度； 2）冰缘撤退和海洋变化的阶段； 3）区域地质，地貌和冰动力学对冰块静修的影响。早期的职业领导力（在高级导师的支持下）是该项目的核心，其中三名美国助理教授和一名博士后研究员指挥船上运营并率先率先进行后抛弃后科学。一半的海科学党将是毕业生和本科生。从Baffin湾获取第一个基于美国的沉积物核心以及美国设施和数据库中数据的档案和数据将为NSF社区提供多样化的高纬度研究机会，确保该项目的持续遗产。该奖项反映了NSF的立法任务，并通过使用基础的知识效果来评估支持NSF的立法任务，并值得通过评估来进行评估。