Microseism source estimated with three-component broadband seismometer array in Fujian and its adjacent areas

Ambient noise tomography has been widely applied, but the distribution of noise sources has an important impact on its accuracy, so it is necessary to carry out related studies. In this paper, continuous records from 94 broadband seismic stations in Fujian and its adjacent area in 2016 were used, and a three-component record polarization analysis method was used to analyze back-azimuth of microseism in the frequency ranges of 0.085-0.2Hz and 0.2-0.5Hz in this region, and its seasonal changes were analyzed. It was found that the seasonal variation of noise source in the frequency range of 0.085-0.2Hz was large, with winter noise mainly coming from Alaska, and summer and autumn noise mainly coming from the southern Indian Ocean and the area near Antarctica. The seasonal variation of noise source direction in the frequency range of 0.2-0.5Hz was small, mainly from the southeast, indicating that its main source may be the coastal waters of Southeast China. It was found in the study that there were significant deviations in some station directions, which were caused by the 180° fuzziness problem of the polarization analysis method. Combining with the asymmetry of the noise cross-correlation function, and the results of array clustering analysis during Typhoon Moranti's passage, it was verified.