Microseismic sources in North Atlantic Ocean

Abstract:

Studying the location, strength and variation of microseismic signals originated in the ocean is important in understanding generation mechanism of microseisms. We identify some microseismic signals from North Atlantic Ocean (NAO) based on the seismic data recorded in 439 EarthScope stations in the United States and 15 permanent stations in Greenland. Among EarthScope stations, microseismic signals are found correlated but only within close azimuths, with the directions of the correlated station pairs pointing to NAO, indicating presence of microseismic sources in NAO. The sources are active in some time periods and quite in others. Travel time analysis between the correlated station pairs further indicates that the observed microseismic signals propagate with a velocity of 3.3 km/s, consistent with surface Rayleigh wave. In Greenland stations, the signals are more correlated between the stations along the eastern coastline. In this presentation, we report location, strength and temporal change of the microseismic sources determined by back projecting the energy of cross-correlations of the sets of stations in the USA and Greenland.