Deglacial to Recent Paleoceanography of the Sabrina Coast, East Antarctica: A Multi-proxy Study of Ice-ocean Interactions at the Outlet of the Aurora Subglacial Basin

东南极洲萨布丽娜海岸的冰川消退到近期古海洋学：极光冰下盆地出口处冰-海洋相互作用的多代理研究

• 批准号: 1744970
• 负责人: Amelia Shevenell
• 金额: $ 30.51万
• 依托单位: University of South Florida
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1744970&HistoricalAwards=false
• 关键词: Deglacial; Recent; Paleoceanography; Sabrina; Coast

Glacial retreat in West Antarctica is correlated with ocean warming; however, less is known about the ocean's effect on East Antarctica's glaciers including Totten Glacier located on the Sabrina Coast. The retreat of Totten Glacier has global significance as the glacier drains a sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by as much as 3.5 meters. This study looks to determine the influence of ocean temperatures on East Antarctic glaciers, including Totten Glacier, over the last ~18,000 years by studying seafloor sediment around Antarctica. These sediments, or muds, include the remains of microscopic marine organisms as well as tiny particles originating from eroded Antarctic bedrock. These muds provide a record of past environmental changes including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers will refine and test new methods for measuring ocean temperature from the sediments to better understand the influence of ocean temperatures on East Antarctic glacier response. Results will be integrated into ice sheet and climate models to improve the accuracy of ice sheet modeling efforts and subsequent sea level predictions. Results from this project will be disseminated at scientific conferences, in the scientific literature, and more broadly to the general public via the St. Petersburg Science Festival and at the Oceanography Camp for Girls. The influence of ocean temperatures on East Antarctic glaciers is largely unknown. This research focuses on ice-proximal Antarctic margin paleoceanographic proxy calibration and validation, which will improve understanding of past ocean-ice sheet interactions on a variety of timescales. In this project, researchers from the University of South Florida will (1) further develop and refine two ocean temperature proxies, foraminifer Mg/Ca and TEX86, for use in ice-proximal Antarctic continental margin sediments and (2) investigate deglacial to present (~18-0 ka) ocean-ice interactions at the outlet of the climatically sensitive Aurora Subglacial Basin. The proposed research utilizes sediment trap, sediment core, and physical oceanographic data previously collected from the Sabrina Coast continental shelf during NSF-funded cruise NBP14-02. Studies of existing sediment cores will integrate multiple paleotemperature, meltwater/salinity, nutrient, bottom water oxygen, and sea ice proxies with geophysical and lithologic data to understand past regional ocean-ice interactions. While the recent international Antarctic research focus has been on understanding the drivers of West Antarctic Ice Sheet retreat, models suggest it would be imprudent to ignore the East Antarctic Ice Sheet, which is proving more sensitive to climate perturbations than previously realized.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.

南极西部的冰川静修与海洋变暖有关。然而，对于海洋对南极洲东部冰川的影响，包括位于萨布丽娜海岸的托特冰川的影响鲜为人知。由于冰川排干了东南极冰盖的一个部门，托特冰川的撤退具有全球意义，其中含有足够的冰，可以将全球海平面提高3.5米。这项研究旨在通过研究南极洲周围的海底沉积物来确定在过去的18，000年中，海洋温度对包括热冰川在内的东南极冰川的影响。这些沉积物或泥浆包括微观海洋生物的残留物以及源自侵蚀的南极基岩的微小颗粒。这些泥浆提供了过去的环境变化的记录，包括海洋温度以及冰川的前进和撤退。科学家使用各种物理和化学分析来确定这种泥浆已被沉积了多久，该位置的海洋温度以及冰川冰的相对位置。在该项目中，研究人员将完善和测试新方法，以测量从沉积物中的海洋温度，以更好地了解海洋温度对东极冰川东部冰川反应的影响。结果将集成到冰盖和气候模型中，以提高冰盖建模工作的准确性以及随后的海平面预测。该项目的结果将在科学会议，科学文献中通过圣彼得堡科学节和海洋学训练营传播给公众。海洋温度对南极冰川东部的影响在很大程度上是未知的。这项研究的重点是南极冰的冰缘古环图校准和验证，这将提高人们对各种时标上过去的海冰纸相互作用的理解。在该项目中，南佛罗里达大学的研究人员（1）将进一步开发和完善两个海洋温度代理，有孔虫mg/ca和tex86，用于冰果质南极的大陆边缘沉积物，以及（2）研究冰期的冰期植物相互作用（〜18-0 ka）的海洋冰相互作用。拟议的研究利用了先前从Sabrina Coast Coarnental Banfel收集的沉积物陷阱，沉积物核心和物理海洋数据，在NSF资助的Cruise NBP14-02期间。现有沉积物核心的研究将与地球物理和岩性数据相结合多种古温核，熔融/盐度，营养，底部水氧和海冰代理，以了解过去的区域海冰相互作用。虽然最近的国际南极研究重点一直在理解南极冰盖撤退的驱动因素上，但模型表明，忽略东南极冰盖是不明智的，事实证明，这对气候扰动的敏感性比先前所实现的更为敏感。该奖项反映了NSF的法定任务，并通过评估了基础的范围，并且对基金会的范围进行了评估，并构成了基金会的支持。