Collaborative Research: Geochemical Consequences of Extensive Gas Hydrate Formation in Sediments of the Cascadia Accfetionaly Prism

9731157托雷斯 为了量化交换的流体和溶解成分从卡斯卡迪亚边缘水合物领域的上覆水柱的多调查程序的目的是测量这种交换在卡斯卡迪亚地区的各种条件下。 一个为期2年的实地项目将部署海底装置，对流体排放进行采样。 重力、推压和多岩心将用于评估大陆边缘沉积物中混合CH 4-H2S水合物的近地表形成和分解如何影响海底通量和早期成岩反应。 第一年收集的数据将用于评估水合物区成分释放的空间变化，这种变化在活跃的喷口可能最为显著。 这些结果将1）确定在随后两次访问该地区期间进行时间变异性研究的理想地点，以及2）确定以下现场计划中部署的长度和数量。 卡斯卡迪亚边缘的不同环境，沿着时空实验设计，将能够评估卡斯卡迪亚边缘广泛水合物形成对海底元素移动、运输和释放的影响。 这方面的知识在全球范围内更广泛的问题的应用，水合物地球化学是全球碳预算，气候变化模型，沉积物边坡稳定性和能源问题的重要相关性。

9731157 Torres To quantify the exchange of fluids and dissolved constituents from the Cascadia margin hydrate field to the overlying water column a multi-investigator program is designed to measure this exchange under a variety of conditions within the Cascadia region. A 2-year field program will deploy benthic devices that sample fluid discharge. Gravity, push and multicores will be used to assess how near-surface formation and decomposition of a mixed CH4-H2S hydrate in continental margin sediments influences benthic fluxes and early diagenetic reactions. The data collected during the first year will be used to assess the spatial variations of constituent release from the hydrate field, variations that are likely to be most significant at active venting sites. These results will 1) identify ideal sites for temporal variability studies to be conducted during two subsequent visits to the area, and 2) define the length and number of deployments in the following field programs. The different environments present in the Cascadia margin, along with the spatial-temporal experimental design will enable assessment of the effect of widespread hydrate formation in the Cascadia margin on element mobilization, transport, and release at the seafloor. This knowledge has applications for broader issues on a global scale, as hydrate geochemistry is of significant relevance in global carbon budgets, climate change models, sediment slope stability, and energy resource issues.