LGM and Deglacial Radiocarbon from U-series Dated Drake Passage Deep-sea Corals

该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。该提案寻求资金，以继续对研究巡航期间在德雷克海峡收集的深海珊瑚进行后续分析工作。该项目的目标是古气候研究，希望在冰川和冰川消退期间限制南大洋放射性碳含量的深度结构和时间演变。放射性碳是过去气候的多用途示踪剂；它的放射性衰变提供了一个内部时钟来评估过程的速率，它可以用来追踪碳在地球系统中的运动。它通过空气-海洋气体交换进入海洋，因此，限制这一过程将减少表层和深层水域的放射性碳含量。南大洋是深海和大气储层之间热量和碳交换的关键位置，在那里形成的深水填补了全球深海和中大洋的大量水域。由于强大的洋流往往冲刷掉沉积物，碳酸盐保存有限，放射性碳储集层的年龄很难得到约束，许多传统的古海洋学技术变得不切实际。为了减轻这些困难，提出了分析深海珊瑚骨架化学成分的方法。它们的文石骨架可以用u系列衰变来精确测定年代，再加上放射性碳分析，就可以计算出过去水柱中C14/C12的比例。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The proposal seeks funds to continue a follow-up analytical work of deep-sea corals collected in the Drake Passage during a research cruise. The project's goal is paleo-climate research looking to constrain the depth structure and time evolution of the radiocarbon content of the Southern Ocean during the glacial and deglaciation. Radiocarbon is a versatile tracer of past climate; its radioactive decay provides an internal clock with which to assess the rates of processes, and it can be used to trace the movement of carbon through the Earth's system. It enters the ocean through air-sea gas exchange, so processes that limits this will, therefore, reduce the radiocarbon content of both surface and deep waters. The Southern Ocean is a critical location for exchange of heat and carbon between the deep-ocean and atmospheric reservoirs, and the deep waters formed there fill large volumes of the global deep and intermediate oceans. As strong currents tend to scour away sediments, carbonate preservation is limited, and radiocarbon reservoir ages are poorly constrained, many traditional paleoceanographic techniques become impractical. It is proposed to alleviate these difficulties analyzing the chemical composition of deep-sea coral skeletons. Their aragonitic skeletons can be precisely dated using U-series decay, and when coupled with radiocarbon analyses will allow to calculate the C14/C12 ratio of the past water column.