Collaborative Research: IODP Expedition 329 Objective Research on Supply of H2 by Water Radiolysis in Subseafloor Sediment of the South Pacific Gyre

合作研究：IODP Expedition 329 南太平洋环流海底沉积物中水辐射解供氢的客观研究

• 批准号: 1130531
• 负责人: Andrew Kurtz
• 金额: $ 16.42万
• 依托单位: Trustees of Boston University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1130531&HistoricalAwards=false
• 关键词: Collaborative; Research; IODP; Expedition; 329; Collaborative; Research; IODP; Expedition; 329

Intellectual MeritThe South Pacific Gyre (SPG) contains the lowest cell concentrations and lowest rates of microbial activity ever encountered in shallowly-buried marine sediment. However, the electron donors that sustain its subseafloor microbial ecosystem are not fully constrained. In recognition of the importance of this natural laboratory, the Integrated Ocean Drilling Program (IODP) selected the SPG as the target of its first riser-less expedition solely dedicated to study of subseafloor life (Expedition 329).This Expedition Objective Research (EOR) proposal has one fundamental objective: To quantify the extent to which subseafloor sedimentary communities of the SPG may be supplied with H2 by water radiolysis.In addressing this objective, the following testable hypotheses are posed:1) H2 is produced by water radiolysis at significant rates relative to other electron donorsin the organic-poor subseafloor sediment of the SPG.2) At some depth below seafloor, the production rate of H2 by water radiolysis exceedsthe availability of other electron donors (organic matter and reduced minerals).To test these hypotheses, this work will focus on four related activities:(1) Precise and accurate quantification of radioactive element concentrations and sedimentary grain size,(2) Quantification of alpha particle (4He) fluxes from the sediment to the interstitial water,(3) Refinement of H2 yield calculations by experimental radiation of representative SPGsediment samples, and(4) Quantification of the potential importance of radiolytic H2 to the subseafloor sedimentary communities by direct comparison of calculated H2 yields to shipboard H2 concentration data and rates of organic matter oxidation derived from shipboard data.This study will advance understanding of the subsurface world by (i) placing a clear boundary on the extent to which subseafloor sedimentary life may be energetically independent of the surface photosynthetic world and (ii) advancing understanding of the sources of microbial energy in sediment of Earth?s largest oceanic province. Because electron donor fluxes are so low in SPG sediment, this research may also help to constrain the limits to life.Broader Impacts, Education, and Data ManagementThis project will fully answer one of the primary objectives of IODP Expedition 329 by quantifying the production of H2 by water radiolysis in SPG sediment. It will address another of the expedition?s primary objectives by advancing understanding of the habitats and rates of metabolic activities in this very large low-energy environment. The project will heighten collaborations between URI (an EPSCoR institution), BU, and our Exp. 329 collaborators from throughout the U.S., Europe, Asia and Australia. The project will have strong training impacts. Graduate students will be integral project members. Undergraduates will be included as thesis advisees, work-study students, paid laboratory assistants, nationally competed NSF-sponsored GSO Summer Undergraduate Research Fellows, and through our courses. The URI Geobiology website will expand to include focus on this project. We will present our results to audiences via guest lectures and the Internet. Significant findings will be submitted for publication beginning in the second year of the project. To ensure accessibility to the scientific community and the public, data will be deposited into the SedDB database and samples will be catalogued through SESAR.

智力优点南太平洋Gyre（SPG）包含浅水海洋沉积物中遇到的微生物活性最低和最低的微生物活性率。但是，维持其子叶中微生物生态系统的电子供体并未完全受到限制。 In recognition of the importance of this natural laboratory, the Integrated Ocean Drilling Program (IODP) selected the SPG as the target of its first riser-less expedition solely dedicated to study of subseafloor life (Expedition 329).This Expedition Objective Research (EOR) proposal has one fundamental objective: To quantify the extent to which subseafloor sedimentary communities of the SPG may be supplied with H2 by water radiolysis.In addressing提出了这一目标，以下可检验的假设是：1）H2是由水放射分解以显着的速率产生的，相对于其他电子供体，Spg.2）在海底以下的某个深度下，H2的生产速率，水的生产速率，水辐射量超过了其他测试供体的供应（这些供体），这些供体的可用性（这些供应量）（这些有机物）。活动：（1）对放射性元件浓度和晶粒尺寸的准确定量，（2）定量α颗粒（4HE）从沉积物到间质水的通量（4He）通量，（3）通过实验性的SPGSEDEMENTS的实验辐射来对H2的辐射进行降低，以及（4）雷神对置于雷神的延迟，以及（4）置于雷神的延迟，（4）计算出的H2屈服于船上H2浓度数据和从船舶数据中得出的有机物氧化的速率。这项研究将通过（i）在（i）在地下沉积物中施加一个明确的边界来提高对地下世界的了解，在多大程度上可以在多大程度上能够在多大程度上可以在多大程度上独立于表面光合物世界和（ii）在SESSERICT of SEARIMENT中的SEARCENT？由于电子供体通量在SPG沉积物中如此之低，因此这项研究也可能有助于限制生命的局限性。Boader的影响，教育和数据管理将通过SPG沉积物中的水分溶解来量化H2的产生IODP Expedition 329的主要目标之一。它将通过在这个非常大的低能环境中促进对栖息地的了解和代谢活动率的理解来解决另一个探险的主要目标。该项目将加强URI（EPSCOR机构），BU和我们的Exp之间的合作。来自美国，欧洲，亚洲和澳大利亚的329名合作者。该项目将产生强大的培训影响。研究生将成为不可或缺的项目成员。本科生将被包括在论文建议，工作学生，有偿实验室助理，全国竞争的NSF赞助的GSO夏季本科生研究研究员以及通过我们的课程中。 URI地球生物学网站将扩展到关注该项目。我们将通过来宾讲座和互联网向观众提供结果。从项目的第二年开始，将提交重大发现以供出版。为了确保科学界和公众的访问性，数据将存放到SEDDB数据库中，并将通过SESAR对样品进行分类。