Collaborative Research: Evolution and Hydration of the Juan de Fuca Crust and Uppermost Mantle: A Plate-Scale Seismic Investigation from Ridge to Trench

俯冲是洋壳和上地幔在岛弧边缘(如日本和苏门答腊岛)或大陆边缘被消耗的过程，因为沿着美国西北海岸，俯冲引起强烈的火山喷发和巨大的？巨型逆冲？地震和海啸。最近，印度尼西亚、日本和智利发生了戏剧性的俯冲破坏效应的示威活动。从俯冲板块释放的水是这些事件的重要因素，但人们对此知之甚少；这次对胡安德富卡板块的地震调查具有明确的目标，即从板块在海脊的形成，通过板块随着年龄的变化和水化，到板块沿卡斯卡迪亚边缘的俯冲。由于卡斯卡迪亚发生大地震的风险很高，更好地了解水在俯冲过程中的作用是这次调查的主要和更广泛的影响。该项目也是卡斯卡迪亚倡议的重要附属项目，该倡议是一项多年部署的陆上和近海仪器，以研究卡斯卡迪亚地区的结构和地震活动。

Subduction is a process in which oceanic crust and upper mantle are consumed beneath the margins of island arcs, such as Japan and Sumatra, or the margins of continents, as along the northwest coast of the U.S. Subducton gives rise to violent volcanic eruptions as well as great ?megathrust? earthquakes and tsunamis. Dramatic demonstrations of the destructive effects of subduction have occurred recently in Indonesia, Japan, and Chile. Water released from the subducted plate is a significant, but poorly understood, contributor to these events; this seismic survey of the Juan de Fuca Plate has the specific aim of characterizing the plate from its formation at the ridge, through alteration and hydration of the plate as it ages, to subduction of the plate along the Cascadia margin. Owing to the very high risk of large earthquakes in Cascadia, improved understanding of the role of water in the subduction process is a primary broader impact of the survey. The project is also an important adjunct to the Cascadia Initiative, a multi-year deployment of instruments both onshore and offshore to study the structure and seismicity of the Cascadia region.