Collaborative Research: Role of the Central Scotia Sea Floor and North Scotia Ridge in the Onset and Development of the Antarctic Circumpolar Current

合作研究：中部斯科舍海底和北斯科舍海脊在南极绕极流发生和发展中的作用

• 批准号: 1246111
• 负责人: Ian Dalziel
• 金额: $ 68.43万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1246111&HistoricalAwards=false
• 关键词: Collaborative; Research; Role; Central; Scotia

Intellectual Merit: Opening of Drake Passage and the West Scotia Sea south of Tierra del Fuego broke the final continental barrier to onset of a complete Antarctic Circumpolar Current (ACC). Initiation of the ACC has been associated in time with a major, abrupt, drop in global temperatures and the rapid expansion of the Antarctic ice sheets at 33-34 Ma. Events leading to the formation of the Drake Passage gateway are poorly known. Understanding the tectonic evolution of the floor of the Central Scotia Sea (CSS) and the North Scotia Ridge is a key to this understanding. Previous work has demonstrated that superimposed constructs formed a volcanic arc that likely blocked direct eastward flow from the Pacific to the Atlantic through the opening Drake Passage gateway as the active South Sandwich arc does today. The PIs propose a cruise to test, develop and refine, with further targeted mapping and dredging, their theory of CSS tectonics and the influence it had on the onset and development of the ACC. In addition they propose an installation of GPS receiver to test their paleogeographic reconstructions and determine whether South Georgia is moving as part of the South American plate. Broader impacts: A graduate student will be involved in all stages of the research. Undergraduate students will also be involved as watch-standers. A community college teacher will participate in the cruise. The PIs will have a website on which there will be images of the actual ocean floor dredging in operation. The teacher will participate with web and outreach support through PolarTREC. Results of the cruise are of broad interest to paleoceanographers, paleoclimate modelers and paleobiogeographers.

智力优势：德雷克海峡和火地岛以南的西斯科舍海的开放打破了完整的南极绕极流（ACC）爆发的最后大陆屏障。 ACC 的启动与全球气温突然大幅下降以及 33-34 Ma 南极冰盖的快速扩张有关。导致德雷克海峡门户形成的事件鲜为人知。了解中部斯科舍海海底 (CSS) 和北斯科舍海脊的构造演化是实现这一认识的关键。之前的研究表明，叠加的构造物形成了一条火山弧，很可能阻止了从太平洋通过开放的德雷克海峡门户直接向东流向大西洋的火山弧，就像今天活跃的南桑威奇弧一样。 PI 提议通过一次巡航来测试、开发和完善他们的 CSS 构造理论及其对 ACC 的产生和发展的影响，并进一步进行有针对性的测绘和疏浚。此外，他们还建议安装 GPS 接收器来测试他们的古地理重建结果，并确定南乔治亚岛是否正在作为南美板块的一部分移动。更广泛的影响：研究生将参与研究的所有阶段。本科生也将作为值班人员参与其中。一名社区大学老师将参加这次巡游。 PI 将建立一个网站，上面将提供实际海底疏浚作业的图像。教师将通过 PolarTREC 参与网络和外展支持。这次航行的结果引起了古海洋学家、古气候建模者和古生物地理学家的广泛兴趣。