Location of high‐frequency P wave microseismic noise in the Pacific Ocean using multiple small aperture arrays

Abstract

AbstractWe investigate source locations of P wave microseisms within a narrow frequency band (0.67–1.33 Hz) that is significantly higher than the classic microseism band (~0.05–0.3 Hz). Employing a backprojection method, we analyze data recorded during January 2010 from five International Monitoring System arrays that border the Pacific Ocean. We develop a ranking scheme that allows us to combine beam power from multiple arrays to obtain robust locations of the microseisms. Some individual arrays exhibit a strong regional component, but results from the combination of all arrays show high‐frequency P wave energy emanating from the North Pacific basin, in general agreement with previous observations in the double‐frequency (DF) microseism band (~0.1–0.3 Hz). This suggests that the North Pacific source of ambient P noise covers a broad range of frequencies and that the wave‐wave interaction model is likely valid at shorter periods.