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.

知识分子的优点：Drake Passage和Tierra del Fuego以南的西斯科舍省海的开放打破了最终的大陆屏障，以发作完整的南极圆形极性电流（ACC）。 ACC的启动及时与全球温度的重大，突然下降以及南极冰盖的迅速扩张有关。导致Drake Passage Gateway形成的事件众所周知。了解斯科舍省中部（CSS）和北斯科舍省山脊的构造演变是这种理解的关键。先前的工作表明，叠加的结构形成了一个火山弧，可能会通过开放的Drake Passage Gateway挡住了从太平洋到大西洋的直接向东流，因为活跃的South Sandwich Arc今天所做的。 PI提出了一项巡游，以进一步的针对性的映射和挖泥，其CSS构造理论及其对ACC的发作和发展产生的影响。此外，他们建议安装GPS接收器，以测试其古地理重建，并确定南乔治亚是否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各个阶段。本科生还将作为守望者参与。社区大学老师将参加巡游。 PI将有一个网站，其中将有实际的海底挖泥的图像。老师将通过Polartrec参加网络和外展支持。巡航的结果对古环摄影师，古气候建模者和古生物地理学家引起了广泛关注。