Investigation of Fluid Sources and Movement at the Cascadia Margin

在沿俄勒冈州、华盛顿州和不列颠哥伦比亚省海岸的卡斯卡迪亚边缘吸积棱柱，对喷口地点流体排放速率的直接测量表明，流速比沉积沉积物局部孔隙度减少所预测的流速高3-6个数量级。该奖项将评估这一差异的两种可能的解决方案：流体从断裂带深处的迁移或由于密度驱动的流动而导致的近地表海水补给。沿断层带的迁移将通过对海洋钻探计划在吸积棱镜中钻孔进行的流量测试来评估。地表补给将通过测量边缘活动喷口周围的现场渗透率来评估。该项目的现场部分将利用研究潜水器阿尔文。

At the Cascadia Margin accretionary prism along the coasts of Oregon, Washington, and British Columbia, direct measurements of fluid discharge rates from vent sites indicate flow rates 3-6 orders of magnitude greater than those predicted by local porosity reduction in accreting sediments. This award will evaluate two possible solutions to this discrepancy: fluid migration from depth along a fault zone or near surface seawater recharge due to density-driven flow. Migration along a fault zone will be evaluated through discharge tests to be performed on boreholes drilled into the accretionary prism by the Ocean Drilling Program. Surface recharge will be evaluated by measuring in situ permeability around active vents on the margin. The field portion of this project will utilize the research submersible Alvin.