Hybrid Kinematic-Dynamic Approach to Seismic Wave-Equation Modeling, Imaging, and Tomography

الملخص EN

Estimation of the structure response to seismic motion is animportant part of structural analysis related to mitigation ofseismic risk caused by earthquakes.

Many methods of computingstructure response require knowledge of mechanical properties ofthe ground which could be derived from near-surface seismicstudies.

In this paper we address computationally efficientimplementation of the wave-equation tomography.

This method allowsinverting first-arrival seismic waveforms for updating seismicvelocity model which can be further used for estimating mechanicalproperties.

We present computationally efficient hybridkinematic-dynamic method for finite-difference (FD) modeling ofthe first-arrival seismic waveforms.

At every time step the FDcomputations are performed only in a moving narrowband followingthe first-arrival wavefront.

In terms of computations we get twoadvantages from this approach: computation speedup and memorysavings when storing computed first-arrival waveforms (it is notnecessary to make calculations or store the complete numericalgrid).

Proposed approach appears to be specifically useful forconstructing the so-called sensitivity kernels widely used fortomographic velocity update from seismic data.

We then apply theproposed approach for efficient implementation of thewave-equation tomography of the first-arrival seismic waveforms.