Finite Element Reverse Time Imaging for Earthquake Sources and Scatterers

Hung Bor-Shouh,Yeong Tein Yeh

doi:10.3319/tao.1991.2.1.17(t)

Abstract

Finite Element Reverse Time Imaging for Earthquake Sources and Scatterers

Highlights

Earthqua ke sources and earth structure inversion are active research top ics in seismology
The computational accuracy of free surface response is important for forward modeling and for reverse time imaging
The traction boundary condition of the free surface is automatically satisfied in the finite element formulation for wave equations but is not always so suitable for the finite difference method (FDM) or pseudo-spectrum method (PSM) (Kosloff et al, 1990)

Summary

INTRODUCTION

Earthqua ke sources and earth structure inversion are active research top ics in seismology They may be determined by the extrapolation of observed wavefield backward in time to obtain an image of sources or niedia scatterers using numerical methods. Time imaging, a kind of backward propagation, solves the wavefield of a given space model based on the wave equation using time traces for the observation points. A method for a source parameter inversion based on reverse time propagation was first proposed by McMechan (1982) and by McMechan et al (1985) for real earthquake data, and extended to elastic cases by Hu and McMechan (1988). We dis cussed the possibility of using the reverse time imaging technique on real data (such as the SMART-1 array data) for source rupture inversion

THEORY

DISCUSSION AND CONCLUSIONS