Synthesizing High-Frequency (1-25 HZ) Regional Phases at Large Distances (>1000 KM) Using Generalized Screen Propagators (GSP)
Abstract
Based on the half-space screen propagator developed in our previous project, we successfully extended the method to the case of irregular surface topography by the conformal and non-conformal topographic transforms. Its validity and potential applications have been numerically demonstrated by comparing with the boundary element method. The new method can handle combined effects of small-scale heterogeneities (random media) and rough random topography on Lg wave propagation. It is also 2-3 orders of magnitude faster than the finite difference method. In the P-SV wave case, reflected plane waves from a free surface are incorporated into the elastic screen method for Lg wave simulation. Due to the presence of a surface wave (Rayleigh wave), both the real and imaginary pans of the wavenumber must be included. Body waves including reflected and convened waves are calculated using real wavenumber integration; surface wave are calculated with imaginary wavenumber integration. The comparison between results from numerical test and the wavenumber integration method shows excellent agreement. Numerical results show that this is a promising method for simulating path effects in different regions for various monitoring discriminants such as Pn/L or Sn/Lg, etc.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2004
- Accession Number
- ADA438856
Entities
People
- Ru-shan Wu
- Xianyun Wu
- Xiao-bi Xie
Organizations
- University of California, Santa Cruz