Late Quaternary Evolution of the Lambert Glacier/Amery Ice Shelf System, Prydz Bay, Antarctica

学术价值：南大洋过程在晚第四纪冰期-间冰期气候变化中起着重要作用。然而，新上涌的温暖的富含营养的环极深水对南极冰冻圈的直接影响仍然是推测性的。PI提议验证环极深水产生的海洋热量对南极洲物质平衡产生负面影响的假设。通过对南极边缘沉积物进行精确定年的晚第四纪古海洋学研究，以及在南极Prydz海峡现有的三个冰川海洋沉积物岩心上测量的一套地球化学代用物，对冰川消融期间的冰原进行了研究。具体来说，PI将利用这些数据重建Lambert冰川/Amery冰架系统的晚第四纪历史；评估末次冰消期Lambert冰川/Amery冰架系统退缩的时间、速度和方式，并评估晚第四纪环极深水入侵对Lambert冰川/Amery冰架系统的影响。硅藻结合放射性碳和光激发发光技术将用于获得Prydz水道硅质泥质软泥层的精确地层年龄控制。此外，PI将测量沉积的10Be浓度，以确定硅质泥泥单元的起源，并追踪冰架前沿位置的过去变化。更广泛的影响：该提案将支持早期职业女性科学家，并将为女性/少数民族研究生和本科生提供专业发展和研究经验。PI将利用USF？’s海洋学女孩营。

Intellectual Merit: Southern Ocean processes play an important role in Late Quaternary glacial-interglacial climate change. However, the direct influence of newly upwelled warm nutrient-rich Circumpolar Deep Water on the Antarctic cryosphere remains speculative. The PI proposes to test the hypothesis that Circumpolar Deep Water-derived ocean heat negatively impacts the mass-balance of Antarctica?s ice sheets during deglaciations using precisely dated late Quaternary paleoceanographic studies of Antarctic margin sediments and a suite of geochemical proxies measured on three existing glacial marine sediment cores from the Prydz Channel, Antarctica. Specifically, the PI will use these data to reconstruct the Late Quaternary history of the Lambert Glacier/Amery Ice Shelf system; evaluate the timing, speed, and style of retreat of the Lambert Glacier/Amery Ice Shelf system during the last deglaciation, and to assess the impact of Circumpolar Deep Water intrusions on the Lambert Glacier/Amery Ice Shelf system in the Late Quaternary. Diatom bound radiocarbon and optically stimulated luminescence techniques will be used to obtain precise stratigraphic age control for the Prydz Channel siliceous muddy ooze intervals. In addition, the PI will measure sedimentary 10Be concentrations to determine the origin of the siliceous muddy ooze units and to track past changes in the position of the ice shelf front.Broader impacts: This proposal will support an early career female scientist and will provide professional development and research experiences for women/minority graduate and undergraduate students. The PI will take advantage of USF?s Oceanography Camp for Girls.