Collaborative Research: Reorganization of deepwater circulation in response to the opening of Southern Ocean passages in the middle/late Eocene (40-33 Ma)

该奖项由2009年《美国复苏和再投资法案》（公法111-5）资助。该奖项支持对始新世南大洋通道开放的深水环流响应的调查。PI将生成多个海洋盆地始新世中晚期的底栖有孔虫稳定同位素数据，以检验以下假设：（1）内部分层的新生代海洋结构开始于约40 Ma，这是对相对于北方成分水而言南方成分水密度增加的响应;（2）随着南方海洋门户逐渐加深，盆地间氧同位素梯度在始新世晚期逐渐增加，使原南极绕极流得以发展和加强。所产生的数据将揭示海洋环流变化与碳酸盐补偿深度所反映的海洋碳循环变化之间的关系，以及更明确的海洋内部结构和相关营养物分布的发展，作为这些变化的一种强迫机制。更广泛的影响包括博士生的教育和培训，本科生参与实验室研究，并通过客座讲座和课程开发与当地高中进行外联。

This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).This awards supports an investigation of the deepwater circulation response to the opening of the Southern Ocean passages in the Eocene. The PIs will generate benthic foraminiferal stable isotope data from the middle-late Eocene in multiple ocean basins to test the hypotheses that (1) the internally stratified Cenozoic ocean structure began ~40 Ma in response to increasing dense southern component water relative to northern component water, and (2) interbasinal oxygen isotope gradients gradually increased through the late Eocene as southern ocean gateways progressively deepened, allowing the proto-Antarctic Circumpolar current to develop and strengthen. The data generated will shed light on the relationship between ocean circulation changes and the alteration of the marine carbon cycle as reflected in the carbonate compensation depth, and on the development of a better defined internal ocean structure and associated nutrient distribution as a forcing mechanism for these changes. Broader impacts include education and training of a PhD student, involvement of undergraduates in laboratory research, and outreach to local high schools via guest lectures and curriculum development.