US GEOTRACES Pacific section: Characterizing the redox environment of the eastern tropical Pacific Ocean

US GEOTRACES 太平洋部分：描述东热带太平洋的氧化还原环境

• 批准号: 1235328
• 负责人: Gregory Cutter
• 金额: $ 41.44万
• 依托单位: Old Dominion University Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2017-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1235328&HistoricalAwards=false
• 关键词: US; GEOTRACES; Pacific; section; Characterizing

The 2013 GEOTRACES Eastern Pacific Zonal Transect from Peru to Tahiti will cross an entensive oxygen deficient zone typically described as "suboxic"; however, measurements of sulfate reduction in this region suggest it may have some anoxic characteristics due to the presence of free sulfide. Redox conditions influence the solubility/stability of many trace elements which in turn affects their vertical and horizontal transport. A scientist from Old Dominion University plans to analyze water samples collected during the cruise for dissolved iodate/iodide, arsenic [As(III)/As(V)], selenium [Se(IV, VI), particulate Se(0), and nano- to picomolar hydrogen sulfide speciation (total, free/uncomplexed). These measurements, along with nitrate/nitrite, nitrous oxide, and iron species determined by other participants during the cruise, will be used to constrain the range of redox conditions within the oxygen deficient zone, assess the importance of in-situ reduction versus horizontal advection of the redox species, and the changing redox conditions within the hydrothermal plume of the East Pacific Rise. Availability of this data will also enable other researchers to determine the behavior of other redox sensitive trace elements in the ocean. As regards the broader impacts, in addition to contributing to the overarching goals of the GEOTRACES Program, one postdoc, one graduate student, and one undergraduate student would be supported and trained as part of this project.

2013 GEOTRACES 从秘鲁到塔希提岛的东太平洋纬向横断面将穿过通常被描述为“缺氧”的密集缺氧区；然而，对该区域硫酸盐还原的测量表明，由于游离硫化物的存在，它可能具有一些缺氧特征。 氧化还原条件影响许多微量元素的溶解度/稳定性，进而影响它们的垂直和水平运输。 奥道明大学的一位科学家计划分析航行期间收集的水样中溶解的碘酸盐/碘化物、砷 [As(III)/As(V)]、硒 [Se(IV, VI)、颗粒 Se(0) 和纳米至皮摩尔硫化氢形态（总、游离/未络合）。 这些测量值以及其他参与者在航行期间确定的硝酸盐/亚硝酸盐、一氧化二氮和铁物质，将用于限制缺氧区域内的氧化还原条件范围，评估原位还原与水平平流的重要性氧化还原物质的变化，以及东太平洋海隆热液羽流中氧化还原条件的变化。 这些数据的可用性还将使其他研究人员能够确定海洋中其他氧化还原敏感微量元素的行为。就更广泛的影响而言，除了为 GEOTRACES 计划的总体目标做出贡献之外，作为该项目的一部分，一名博士后、一名研究生和一名本科生将得到支持和培训。