Millenial-Scale Climate and Ocean Changes in the Western North Atlantic

这项提议要求支持一项研究，将布莱克-巴哈马外脊和相邻斜坡的许多岩心的数据结合起来，在中等(~1500米)到深(~4700米)的海洋内，以汇编大西洋西部边界的古水文地理学。再加上附近小巴哈马浅滩400米至1500米深度范围的数据，将形成任何大洋盆地中最详细和最广泛的古水文地貌。对于这一项目，海底有孔虫中的碳同位素将是古营养素的主要示踪剂，而成对的海底和浮游生物放射性碳分析之间的年龄差异将成为通风示踪剂。这些示踪剂将被应用于岩芯采集中的最后一次冰川最大(LGM)水平，以确定深水和中深度水团之间的锋面变化程度。它们还将被应用于大约11,000年前的千年尺度事件(称为年轻仙女座树)，以比较千年尺度与轨道尺度(LGM)的水文变化。最后，将在气候快速反复循环的同位素阶段3(目前约为30至60KYR)评估千年尺度水文变化的程度。

AbstractThis proposal requests support for a study to combine data from many cores from the Blake-Bahama Outer Ridges and the adjacent slope, within the intermediate (~l500m) to deep (~4700m) ocean, in order to assemble a paleohydrography along the western boundary of the Atlantic. This, combined with nearby data from the depth range 400m to 1500m at Little Bahama Bank, will form the most detailed and extensive paleohydrography for any ocean basin. For this project, carbon isotopes in benthic foraminifera will be the main tracer for paleonutrients, and the age difference between paired benthic and planktonic radiocarbon analyses will be a ventilation tracer. These tracers will be applied to the Last Glacial Maximum (LGM) level in the core collection to determine the extent of frontal changes between deep and intermediate depth water masses They will also be applied to the millennial-scale event of about 11,000 14C yrs ago (known as the Younger Dryas) to compare millennial-scale with orbital-scale (LGM) hydrographic changes. Finally, the extent of millennial scale hydrographic changes will be evaluated during isotope Stage 3 (~30 to 60 kyr before present) when climate cycled rapidly and repeatedly.