Thermal Structure of the Cascadia Subduction Zone on the Washington Margin

华盛顿边缘卡斯卡迪亚俯冲带的热结构

• 批准号: 1144164
• 负责人: Harlan Johnson
• 金额: $ 38.78万
• 依托单位: University of Washington
• 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: 2012-07-01 至 2017-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1144164&HistoricalAwards=false
• 关键词: Thermal; Structure; Cascadia; Subduction; Zone

To obtain an accurate estimate of conductive heat flux from the Cascadia accretionary prism, the PIs plan redundant methods to obtain both thermal and fluid flux measurements along a 2.5 D profile of the margin at a single latitude. In this profile they will use thermal blankets suitable for impenetrable sub-stratum, continuous fluid flow meters, multi-core deployments for sediment pore-water chemistry and thermal gradient measurements, and Jason-II heat flow probes. The heat flow and fluid flux data will be obtained at 10 specific equally-spaced depth intervals, along the margin from 2900 m to 500 m depths. The heat flow profile would also coincide spatially with other large-scale NSF programs planned for the Washington corridor at 47°N, including the OBSIP (Ocean Bottom Seismometer) focused deployment site, Endurance Array moorings for OOI, high resolution EM302 bathymetry surveys, and an Open Access 3-D MCS volume using the LANGSETH. The goal would be to obtain data of sufficient quality that downward projection of the surficial thermal gradients to the CSZ décollement and igneous basement can be made with reasonable confidence.The Open Data Access strategy developed by the MCS community is the new paradigm for geophysical data that has wide community interest, and we plan to follow that model. The planned heat flow, fluid flux and companion geophysical data will be made publically available (via GeoPRISM and UW web sites) in preliminary form, within 3 months of the end of the cruise. The project will also incorporate UW graduate and undergraduate students, as well as students from other institutions in the cruises and equipment development. The Grays Canyon area is within the treaty fishing zone of the Quinault Indian Nation, and the PIs plan to include students and teachers from the Tahola High School and Cascadia Community College in the field program.

为了获得从Cascadia振底棱镜中的导电热通量的准确估计，PIS计划冗余方法，以在单个纬度处的边缘的2.5 d轮廓获得热和流体通量测量。在此概况中，他们将使用适合不可穿透的亚层，连续流体流量计的热毯，用于沉积物孔隙水化学和热梯度测量的多核部署以及Jason-II热流动问题。热流和流体通量数据将以10个特定的同等深度间隔获得，并沿着2900 m至500 m的深度获得。热流曲线还将与计划在47°N的华盛顿走廊计划的其他大规模NSF计划在空间上重合，包括OPE（海洋底部地震计）重点部署地点，OOI的耐力阵列系列，高分辨率EM302 EM302测深的测试，以及使用Langseth的开放式3-D MCS量。目的是获得足够质量的数据，即可以以合理的信心向CSZdécollement和火成岩地下室的表面热梯度下降投影。MCS社区开发的开放数据访问策略是具有广泛社区兴趣的地球物理数据的新范式，我们计划遵循该模型。计划的热流，流体通量和伴侣地球物理数据将在巡航结束后的3个月内以初步形式公开提供（通过地理生物和威斯康星大学网站）。该项目还将纳入UW研究生和本科生，以及巡航和设备开发中其他机构的学生。灰色峡谷地区位于奎诺（Quinault Indian Nation）的条约捕鱼区内，PIS计划将塔荷拉高中的学生和老师包括在现场计划中。