GEOTRACES Pacific section: Dissolved and particulate concentrations of selected anthropogenic radionuclides along the U.S. GEOTRACES Peru-Tahiti zonal section

国际GEOTACES计划是一个全球性的海洋微量元素及其同位素地球化学循环研究项目。 2006年，GEOTRACES科学计划将GEOTRACES的使命确定为“查明控制海洋中关键微量元素和同位素分布的过程和量化通量，并确定这些分布对环境条件变化的敏感性”。 为了实现这一使命，科学计划进一步确定了一个主要目标，即确定全球海洋中TEI的浓度和物种形成，以及控制其分布的生物、化学和物理过程。 人为放射性核素（即，在该项目中，哥伦比亚大学拉蒙特-道格拉斯地球观测站的一个研究小组将测量2013年美国地理追踪项目太平洋分区从秘鲁到塔希提岛沿着的溶解态和颗粒态239钚、240钚、237核聚变和137铯的水柱浓度。 对于研究区域的大部分地区来说，这些将是这些放射性核素的基线垂直剖面;也就是说，目前关于其分布的数据很少（如果有的话）。 还将在几个选定地点的表层沉积物中测量这些相同的人为放射性核素。 在可能的情况下，研究小组将把2013年的数据与1972-1973年的测量数据进行比较，从而获得关于控制这些物质分布和归宿的过程的四十年视角。更广泛的影响：该项目将与其他海洋放射化学家进行国际合作。 它还将包括对本科生和高中生进行积极的教育宣传，以提高公众对环境放射性的认识。

The International GEOTACES Program is a global study of the marine biogeochemical cycles of trace elements and their isotopes (TEIs). In 2006, the GEOTRACES Science Plan defined the mission of GEOTRACES to be "To identify processes and quantify fluxes that control the distribution of key trace elements and isotopes in the ocean and to establish the sensitivity of these distributions to changing environmental conditions". To achieve this mission, the Science Plan further sets one of the primary goals to be the determination of the global ocean concentration and speciation of TEIs as well as the biological, chemical, and physical processes governing their distribution. Anthropogenic radionuclides (i.e., those associated with nuclear energy production and defence activities) are included in the Science Plan as "parameters of interest".In this project, a research team at the Lamont-Dougherty Earth Observatory of Columbia University will measure water column concentrations of 239Pu, 240Pu, 237Np, and 137Cs in dissolved and particulate phases along the 2013 US GEOTRACES Pacific zonal section from Peru to Tahiti. For much of the study region, these will be baseline vertical profiles of these radionuclides; that is, very few (if any) data on their distribution are currently available. These same anthropogenic radionuclides will also be measured in surface sediments at a few selected sites. Where possible, the team will compare the 2013 data to measurements made in 1972-1973, thus obtaining a four-decade perspective on processes controlling the distribution and fate of these substances.Broader Impacts: This project will feature international collaboration with other marine radiochemists. It will also include agressive educational outreach to undergraduate and high school students to advance public understanding of environmental radioactivity.