Improving microseismic P wave source location with multiple seismic arrays

Using array analysis, the direction and distance to a seismic P wave source can be determined. However, individual arrays are limited in their geographical coverage and by their resolving capability, which is determined by the array aperture, configuration, and number of stations. We demonstrate these limitations on three large seismic arrays located in Japan, Europe, and California, and find that all give a unique but imperfect insight into the P wave sources acting in the North Pacific. We then combine the data from all three arrays into one beamforming image. The combined images bring together the views offered by each array, providing a concise, comprehensive, and more robust representation of multiple source locations. Next we weight each array for distance in order to optimize the result. Being able to resolve and accurately locate source regions is an important step in being able to use seismic records to monitor ocean wave activity and track storms in real time.