International Research Fellowship Program: Sediment Transport in Marine Environments: Processes, Timescales, and Paleoclimatic Implications

国际研究奖学金计划：海洋环境中的沉积物迁移：过程、时间尺度和古气候影响

• 批准号: 0853110
• 负责人: Victoria Lee
• 金额: $ 16.98万
• 依托单位: Lee Victoria E
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0853110&HistoricalAwards=false
• 关键词: International; Research; Fellowship; Program; Sediment

0853110LeeThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Victoria E. Lee to work with Dr. Gideon M. Henderson at Oxford University in the United Kingdom.The aim of this project is to determine the timescales and processes involved in the formation and evolution of marine sediment deposits. This information is necessary for accurate interpretation of the paleoclimatic and paleoceanographic proxy records hosted in marine sediments. Of particular interest are proxy records in deep-sea drift deposits. Lateral advection of fine-grained sediment to drifts causes high sedimentation rates that are desirable for high-resolution paleoclimate studies. However, this process can also cause spatial and temporal decoupling of proxies associated with different grain sizes ? lateral advection of fine-grained sediment by deep ocean currents can transport older proxies recording non-local environmental conditions to a given depositional site. Therefore, deciphering a given location?s paleoproxy record requires information about the transport history of the fine-grained sediment fraction. The PI is investigating the effects of glacial-interglacial sea level changes on the transport history of the Bermuda Rise sediments, which comprise a deep-sea drift site of paleoclimatic importance. This is being done by applying a suite of relatively new geochemical tools, which are: the uranium-series comminution age method, excess thorium-230 for determining sediment focusing factors, optically stimulated luminescence dating, and compound-specific carbon-14 dating, as well as conventional neodymium and strontium isotopes for provenance. The sum of the information obtained by conducting these measurements will provide quantitative marine sediment transport and storage timescales, insight into the related drift-forming processes, and a better understanding of how to interpret multiproxy paleoclimate records. This has direct relevance for understanding the Earth?s climate system, which presently is of societal concern.

0853110Lee 该奖项根据 2009 年美国复苏和再投资法案（公法 111-5）提供资助。国际研究奖学金计划使美国科学家和工程师能够在国外进行九到二十四个月的研究。 该项目的奖项为联合研究以及使用国外独特或互补的设施、专业知识和实验条件提供了机会。该奖项将支持维多利亚·E·李博士与吉迪恩·M博士合作为期二十四个月的研究奖学金英国牛津大学的亨德森。该项目的目的是确定海洋沉积物形成和演化的时间尺度和过程。 这些信息对于准确解释海洋沉积物中的古气候和古海洋代理记录是必要的。 特别令人感兴趣的是深海漂流沉积物的代理记录。 细粒沉积物向漂移的横向平流会导致高沉积速率，这对于高分辨率古气候研究来说是理想的。 然而，这个过程也会导致与不同粒度相关的代理的空间和时间解耦？深洋流对细粒沉积物的横向平流可以将记录非本地环境条件的较旧代理传送到给定的沉积地点。 因此，破译给定位置的古代理记录需要有关细粒沉积物部分的运输历史的信息。 PI正在调查冰期-间冰期海平面变化对百慕大隆起沉积物迁移历史的影响，百慕大隆起沉积物构成了具有古气候重要性的深海漂移点。 这是通过应用一套相对较新的地球化学工具来完成的，这些工具是：铀系粉碎年龄法、用于确定沉积物聚焦因子的过量钍230、光刺激发光测年法和化合物特异性碳14测年法，如以及常规的钕和锶同位素的来源。 通过进行这些测量获得的信息总和将提供定量的海洋沉积物运输和储存时间尺度，深入了解相关的漂移形成过程，并更好地理解如何解释多代理古气候记录。 这与了解目前受到社会关注的地球气候系统有直接关系。