Resolvability of Multiple Microseismic P-Wave Source Regions with Two Large Seismic Arrays in China and the United States

Abstract

P-wave microseisms are useful for understanding ocean waves. Resolving and locating multiple P-wave source regions using seismic data can provide valuable information about ocean waves. The resolvability of multiple microseismic P-wave source regions depends on the location accuracy and resolution, which can be improved using multiple large seismic arrays. In this article, we investigate the source locations of P-wave microseisms at the period of 5–10 s by combining the backprojection results from two large dense seismic arrays located in China (ChinArray) and the United States (USArray). We independently process data recorded by ChinArray and USArray during a two-year period (2014–2015) that border both the North Pacific and North Atlantic. Then the results are normalized and summed or intersected in the source region to improve the accuracy of the P-wave microseism source locations by reducing the deviation from the velocity structure model and the array response function. The results show that we can resolve two to three sources with a scale of ∼500–1000 km within one large P-wave source region. We also investigate how array parameters such as aperture, interstation spacing, and geographic position affect the detectability and accuracy of the P-wave microseism sources. The discrepancy in P-wave microseism source locations between backprojection observation and ocean model predictions in source number, source scale, and source region scope imply that the ocean model needs to be improved.