Collaborative Research: Resolving Structural Control of Episodic Tremor and Slip Along the Length of Cascadia

Earthscope公司的柔性阵列（Flexible Array）部署了宽带和短周期地震仪器，用于研究Cascadia俯冲带的分段。该实验旨在研究间歇性震颤和滑动与上覆板块的三维结构之间的潜在联系，包括地质地形和与发震行为相关的特征的差异。柔性阵列的部署补充了现有的可移动阵列和永久网络的地震台站，提供了一个均匀密集的网络，典型台站间距为40公里。监测站的覆盖范围从加利福尼亚北部，穿过俄勒冈州，到华盛顿北部边界，从海岸到火山弧的东侧。这种密集的地震台站覆盖，结合来自板块边界观测站的增强GPS仪器，正被用于研究整个卡斯卡迪亚俯冲带的非火山震颤和慢滑事件的时空模式。初步的工作揭示了间歇性震颤和滑动特征的分割，这些特征似乎与俯冲板块无关。上覆大陆板块的地震成像将提供必要的构造控制，以研究其与上板块地质和流变学沿走向变化的潜在关系。

A deployment of broadband and short period seismic instruments from Earthscope's Flexible Array is being used to study segmentation along the length of the Cascadia subduction zone. The experiment is designed to examine the potential links between episodic tremor and slip and the three-dimensional structure of the overriding plate including differences in the geologic terranes and features associated with seismogenic behavior. The Flexible Array deployment complements existing seismic stations from the Transportable Array and permanent networks to provide a uniformly dense network with a typical station spacing of 40 km. Station coverage extends from northern California, through Oregon, to the northern border of Washington, from the coast to the eastern side of the volcanic arc. This dense seismic station coverage, combined with enhanced GPS instrumentation from the Plate Boundary Observatory, is being used to investigate spatial and temporal patterns of non-volcanic tremor and slow slip episodes throughout the entire Cascadia subduction zone. Preliminary work reveals segmentation in the characteristics of episodic tremor and slip which do not appear to correlate with the subducting plate. Seismic imaging of the overriding continental plate will provide the necessary structural control to investigate potential relationships with along-strike variations in geology and rheology of the upper plate.