Full-wavefield tomography for seismic monitoring

摘要

We present a method for updating P- and S-wave velocity models from (micro-) earthquake waveforms recorded on passive seismic arrays using wave-equation migration and image-domain tomographic inversion. Although seismic waves generated from an earthquake are fundamentally an elastic phenomena, we use independent acoustic approximations for both the P- and S-wave propagation. Our method requires no arrival picking and can thus be used with low signal-to-noise data. It also does not rely on initial estimates of the source locations, and neither on origin time nor known events such as perforation shots. This allows for the application of the method in situations with minimal control points, such as induced seismic monitoring. In this paper we present the inversion theory and provide a synthetic example to show its potential applicability.