Coda wave interferometry and constraints on relative earthquake locations

Abstract

The majority of earthquake location techniques, even modern techniques such as double difference, use only a small component of the seismic waveform or seismogram. A new technique to aid earthquake location is coda wave interferometry (CWI). In this method the cross correlation of coda waves, the later arriving waves in a seismogram, are used to directly estimate separations between earthquake sources. An extension of the existing CWI theory is derived to consider the effect of changes in source mechanism. Preliminary testing of the existing and extended CWI is presented. Plans are outlined to use CWI source separation estimates to complement travel time information and constrain earthquake location inversion for groups of earthquakes.