Seismic Wave Propagation on a Laterally Heterogenous Earth

9725496 Dahlen这项研究涉及开发、测试和利用利用三维Frechet核在中间尺度推断地球横向非均质性的方法。通过允许更多的表面波泛音分支的耦合，当前的瞬时核将扩展到更高的射线参数。模射线二象性将通过比较耦合表面波核与基于体波JWKB理论的核来探讨。三维核将开发波形功能，如旅行时残差测量的相互关联的观测和球地合成地震记录。还将进行若干其他理论发展，以便根据诸如全球地震台网和便携式pascal阵列项目等大大改进的宽带数据源开发改进的地球模型。改进的地球模型对于研究板块构造的驱动力是必不可少的，板块构造是地震的能量来源。这项研究是国家减少地震危害计划的一个组成部分。＊＊＊

9725496 Dahlen This research involves the development, testing, and exploitation of methods of inferring the lateral heterogeneity of the earth at intermediate scales, using 3-D Frechet kernels. Current instantaneous kernels will be extended to higher ray parameters by allowing for the coupling of more surface-wave overtone branches. Mode-ray duality will be explored by comparing coupled surface-wave kernels with kernels based upon body-wave JWKB theory. Three- dimensional kernels will be developed for wave-form functionals such as travel-time residuals measured by cross-correlation of observed and spherical-earth synthetic seismograms. Several other theoretical developments will be undertaken to implement the development of improved earth models from the greatly improved broad-band data sources such as the Global Seismic Network and the portable PASSCAL array projects. The improved earth models are essential to investigation of the driving forces of plate tectonics, the energy source for earthquakes. This research is a component of the National Earthquake Hazard Reduction Program. ***