Collaborative Research: Imaging plate boundary processes within the Cascadia subduction zone offshore central Washington with open-access marine seismic data

最近获得的多道地震（MCS）数据的分析将解决一系列的主题，涉及岩石圈的结构和边缘演变沿着卡斯卡迪亚俯冲带的中央WA部分，以及如何将这些与当前的地震活动模式。预计对1 100公里网格的MCS数据进行高级处理将查明板块边界的深度和特征，并将评估目前正在俯冲的沉积物数量。将绘制增生楔内地层的变形图，以跟踪板块相互作用的长期演变。地壳水合作用的估计将从假定的地震速度-孔隙度关系和沿着界面的反射率获得。将绘制显示该区域甲烷水合物分布的地图，其结果将提供一个框架，在此框架内进行其他卡斯卡迪亚地球科学研究，包括地震过程和构造演变，并可能对灾害评估产生影响。虽然这个俯冲带目前的地震活动比世界上其他地区少，但在数百年的时间尺度上，重复的巨型逆冲事件的陆上证据是清楚的，因此重要的是要了解应力积累（地层变形）的历史以及流体沿着断层的程度可能使“润滑”，缓慢的应力释放时期。

Analysis of recently acquired multi-channel seismic (MCS) data will address a series of topics that relate to the structure of the lithosphere and margin evolution along the central WA portion of Cascadia subduction zone and how these relate to current seismicity patterns. Advanced processing of the ~1100 km grid of MCS data is expected to identify the depth and character of the plate boundary and the amount of sediment currently being subducted will be assessed. Deformation of strata within the accretionary wedge will be mapped to track longer-term evolution of the plate interactions. Estimates of crustal hydration will be obtained from assumed seismic velocity - porosity relationships and, along interfaces, reflectivity. Maps showing the distribution of methane hydrates in the region will be produced.Results will provide a framework within which other Cascadia geoscience studies are conducted, both for seismic processes and tectonic evolution, and are likely to have implications for hazard assessment. While this subduction zone currently has less earthquake activity than other zones around the world, onshore evidence of repeated megathrust events is clear over times scales of hundreds of years, so it is important to understand the history of stress buildup (strata deformation) and the extent to which fluids along faults might enable periods of 'lubricated', slow stress release.