3-D Crustal P and S Velocities in Southern California and Their Seismological and Tectonic Implications

本研究将绘制三维纵、横波速度结构图 在南加州的地壳中， 超过150万个P波和S波初至时间， 加州理工学院/美国地质勘探局网络自1981年以来记录的当地事件。 的 大量的数据大小和对完整的三维光线跟踪的需求， 已知的地壳中的大的横向不均匀性造成了 对传统方法的主要计算挑战。 由 创新的主站方法， 然而，P和S结构将同时成像， 该项目涉及总结事件的重新定位。 主 目的是建立P和S地壳速度模型， 加州南部的分辨率比最新的高一个数量级 P速度模型，重新定位地震和重新审查第一- 常规大偏差区域的运动聚焦机制 处理，并深入了解地壳地震构造 通过综合分析所有已知的地球物理和 地质信息 这项研究是一个组成部分， 国家地震减灾计划。

This research will map the 3-D P- and S-wave velocity structures in the crust of southern California by tomographically inverting over 1.5 million P- and S-wave first-arrival times from over 80,000 local events recorded by the Caltech/USGS network since 1981. The massive data size and the demand for a full 3-D raytracing due to known large lateral inhomogeneities in the crust have imposed a major computational challenge to conventional methods. By an innovative Master Station Method of incorporating 3-D ray tracing, however, the P and S structures will be imaged simultaneously in this project with relocation of summarized events. The primary objectives are to construct P and S crustal velocity models for southern California at one order higher resolution than the latest P velocity model, to relocate earthquakes and re-examine first- motion focal mechanisms in areas of large bias by routine processing, and to gain insight into the crustal seismo-tectonic processes through integrated analysis of all known geophysical and geological information. This research is a component of the National Earthquake Hazard Reduction Program.