Collaborative Research: US GEOTRACES PMT: Sources and Rates of Trace Element and Isotope Cycling Derived from the Radium Quartet

GSTDTAP

项目编号	1736321
	Collaborative Research: US GEOTRACES PMT: Sources and Rates of Trace Element and Isotope Cycling Derived from the Radium Quartet
	Willard Moore
主持机构	University of South Carolina at Columbia
项目开始年	2018
	2018-02-01
项目结束日期	2021-01-31
资助机构	US-NSF
项目类别	Continuing grant
项目经费	44067(USD)
国家	美国
语种	英语
英文摘要	The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes in the oceans. Naturally occurring radioactive isotopes of the element radium can be used to measure the rates of important processes in the ocean. In turn, making these rate measurements at the same time as other trace element and isotope data are collected enables a more complete interpretation of these data. The investigators propose to measure the four isotopes of radium -- Ra-223, Ra-224, Ra-226, and Ra-228 -- on a U.S. GEOTRACES expedition from Alaska to Tahiti in 2018. The radium isotope data will be particularly useful in investigating trace element input and removal processes associated with ocean boundaries (rivers, continental shelves, and the ocean bottom) and with mid-ocean ridge hydrothermal vents and the long-range dispersal of their neutrally buoyant plumes. The investigators will also investigate the processes controlling the internal cycling of the longest-lived isotope, Ra-226, compared to the element barium, which has a very similar chemistry to radium. The proposed work would address a number of key questions regarding trace element inputs from ocean boundaries and their potential impact on ocean productivity and biogeochemistry. As iron is an important nutrient for marine phytoplankton, the investigators will quantify the rates of lateral trace element transport from the Gulf of Alaska margin out to and including the offshore High Nutrient Low Chlorophyll region of the subarctic Northeast Pacific Ocean. In the ocean subsurface, they will seek to understand the trace element fluxes associated with high temperature hydrothermal venting, and the rate at which trace elements and isotopes are removed via scavenging along the hydrothermal plume. Lastly, the work will lead to an improved understanding of a marine carbonate sediment dating technique via an investigation of Ra-226 and barium fractionation processes in the upper ocean. The project will involve collaboration between two U.S. institutions and a partner in France who will analyze some of the samples. Two graduate students will participate in the project. Moore will supervise an undergraduate student through the South Carolina Alliance for Minority Participation, and will encourage this student to develop a senior thesis based on their participation in this project.
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/72271
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Willard Moore.Collaborative Research: US GEOTRACES PMT: Sources and Rates of Trace Element and Isotope Cycling Derived from the Radium Quartet.2018.