Evaluation of Cross-Correlation Methods on a Massive Scale for Accurate Relocation of Seismic Events

摘要

Lamont-Doherty Earth Observatory (LDEO) at Columbia University is evaluating a method of locating seismic sources (earthquakes, explosions) based on the use of waveform cross-correlation (WCC) measurements instead of using the conventional measurements of seismic wave arrival time (phase picks). WCC measurements have been demonstrated to be 10 to 100 times more accurate, where they can be used. The principal issue we are exploring is the extent to which a significant fraction of seismicity can be located using WCC measurements. In this second year of the project we have focused on studies of intraplate seismicity in New Madrid (Central United States) and Charlevoix (Eastern Canada). We have also compared our results for these regions, with the results for a separately-funded project to study the seismicity of Northern California.