COLLABORATIVE RESEARCH: IPY: Testing the Polar Gateway Hypothesis: An Integrated Record of Drake Passage Opening & Antarctic Glaciation

合作研究：IPY：测试极地网关假说：德雷克海峡开放的综合记录

• 批准号: 0946339
• 负责人: Howard Scher
• 金额: $ 9.49万
• 依托单位: University South Carolina Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-01-01 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0946339&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; IPY; Testing; Polar

This project studies the relationship between opening of the Drake Passage and formation of the Antarctic ice sheet. Its goal is to answer the question: What drove the transition from a greenhouse to icehouse world thirty-four million years ago? Was it changes in circulation of the Southern Ocean caused by the separation of Antarctica from South America or was it a global effect such as decreasing atmospheric CO2 content? This study constrains the events and timing through fieldwork in South America and Antarctica and new work on marine sediment cores previously collected by the Ocean Drilling Program. It also involves an extensive, multidisciplinary analytical program. Compositional analyses of sediments and their sources will be combined with (U-Th)/He, fission-track, and Ar-Ar thermochronometry to constrain uplift and motion of the continental crust bounding the Drake Passage. Radiogenic isotope studies of fossil fish teeth found in marine sediment cores will be used to trace penetration of Pacific seawater into the Atlantic. Oxygen isotope and trace metal measurements on foraminifera will provide additional information on the timing and magnitude of ice volume changes. The broader impacts include graduate and undergraduate education; outreach to the general public through museum exhibits and presentations, and international collaboration with scientists from Argentina, Ukraine, UK and Germany. The project is supported under NSF's International Polar Year (IPY) research emphasis area on "Understanding Environmental Change in Polar Regions". This project is also a key component of the IPY Plates & Gates initiative (IPY Project #77), focused on determining the role of tectonic gateways in instigating polar environmental change.

该项目研究德雷克海峡的开放与南极冰盖形成之间的关系。它的目标是回答这个问题：三千四百万年前是什么推动了从温室世界到冰库世界的转变？是南极洲与南美洲分离引起的南大洋环流变化，还是大气二氧化碳含量减少等全球性影响？这项研究通过南美洲和南极洲的实地考察以及海洋钻探计划之前收集的海洋沉积物岩心的新工作来限制事件和时间安排。它还涉及广泛的、多学科的分析计划。沉积物及其来源的成分分析将与 (U-Th)/He、裂变径迹和 Ar-Ar 测温法相结合，以限制德雷克海峡边界大陆地壳的隆起和运动。对海洋沉积物岩心中发现的化石鱼牙的放射性同位素研究将用于追踪太平洋海水渗入大西洋的情况。对有孔虫的氧同位素和痕量金属测量将提供有关冰体积变化的时间和幅度的额外信息。 更广泛的影响包括研究生和本科生教育；通过博物馆展览和演示以及与阿根廷、乌克兰、英国和德国科学家的国际合作向公众进行宣传。该项目得到了 NSF 国际极地年 (IPY) 研究重点领域“了解极地环境变化”的支持。该项目也是 IPY Plates & Gates 计划（IPY 项目 #77）的关键组成部分，重点是确定构造门户在引发极地环境变化中的作用。