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

西南极洲的冰川退缩与海洋变暖有关；然而，人们对海洋对包括位于萨布丽娜海岸的托滕冰川在内的东南极洲冰川的影响知之甚少。托滕冰川的退缩具有全球意义，因为它消耗了南极东部冰盖的一部分，其中包含的冰足以使全球海平面上升3.5米。这项研究试图通过研究南极洲周围的海底沉积物来确定在过去18000年里海洋温度对包括Totten冰川在内的南极东部冰川的影响。这些沉积物，或泥浆，包括微观海洋生物的遗骸，以及来自侵蚀南极基岩的微小颗粒。这些泥浆提供了过去环境变化的记录，包括海洋温度和冰川的进退。科学家们使用各种物理和化学分析来确定这些泥浆沉积的时间，该地点的海洋温度，以及冰川冰的相对位置。在这个项目中，研究人员将改进和测试从沉积物中测量海洋温度的新方法，以更好地了解海洋温度对南极东部冰川反应的影响。结果将被整合到冰盖和气候模型中，以提高冰盖建模工作和随后的海平面预测的准确性。该项目的成果将在科学会议上、在科学文献中传播，并通过圣彼得堡科学节和女童海洋学营更广泛地向公众传播。海洋温度对南极东部冰川的影响在很大程度上是未知的。本研究的重点是冰-近端南极边缘古海洋学代理校准和验证，这将提高对过去各种时间尺度上海洋-冰盖相互作用的认识。在这个项目中，来自南佛罗里达大学的研究人员将(1)进一步开发和完善两种海洋温度指标，有孔虫Mg/Ca和TEX86，用于冰-近端南极大陆边缘沉积物；(2)在气候敏感的极光冰下盆地出口研究冰-冰相互作用（~18-0 ka）。拟议的研究利用了沉积物捕集器、沉积物芯和以前在美国国家科学基金会资助的NBP14-02号巡航期间从萨布丽娜海岸大陆架收集的物理海洋学数据。对现有沉积物岩心的研究将整合多种古温度、融水/盐度、营养物质、底水氧和海冰代用物物理和岩性数据，以了解过去区域海洋-冰的相互作用。虽然最近国际南极研究的重点是了解南极西部冰盖退缩的驱动因素，但模式表明，忽视南极东部冰盖是不明智的，因为事实证明，南极东部冰盖对气候扰动比以前认识到的更为敏感。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.