Collaborative Research: Isotope Stage 3 Climate Change in the Western North Atlantic

本提案旨在利用布莱克-巴哈马外脊岩心深度样带的资料，为海洋同位素第3阶段（~25 ~ 65 ka）的千年尺度气候事件研究提供支持。该项目有两个主要目标：(1)通过在有限的地理区域内制作深度剖面来测试第三阶段事件的古水文变化模型；(2)从百慕大上升开始的第三阶段时间序列中调查十年到世纪尺度气候变化的证据。第一个目标将测试一个模型，即大规模冰山的排放，被称为海因里希事件，减少了北大西洋深水浅层和深层成分的产生，而更典型的静态事件只抑制了深层成分。第二个目标将调查来自百慕大隆起的浮游有孔虫中高频氧同位素振荡的证据。为了将这些结果放在气候背景下，我们将开发公海第三阶段的最佳年龄模型，并将我们的新数据与现有的基于烯烃的温度序列和深海通风变化的地球化学代理进行比较。

This proposal seeks support for a study of millennial scale climate events during marine isotope Stage 3 (~25 to 65 ka) from data in a depth transect of cores from the Blake-Bahama Outer Ridges. The project has two main objectives: (1) to test models of paleohydrographic change for Stage 3 events by making depth profiles in a limited geographic area, and (2) to investigate evidence for decade to century scale climate change in a Stage 3 time series from the Bermuda Rise. The first objective will test the model that massive discharges of icebergs, known as Heinrich events reduced production of both shallow and deep components of North Atlantic Deep Water, whereas more typical stadial events suppressed only the deep component. The second objective will investigate evidence for high-frequency oxygen isotopic oscillations in planktonic foraminifer from the Bermuda Rise. To put these results in a climatic context, we will develop the best possible age model for Stage 3 in the open ocean, and compare our new data to both existing alkenone-based temperature series and geochemical proxies for deep ocean ventilation changes.