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A persistent localized microseismic source near the Kyushu Island, Japan
Author(s) -
Zeng Xiangfang,
Ni Sidao
Publication year - 2010
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2010gl045774
Subject(s) - microseism , seismology , geology , bay , amplitude , noise (video) , seismogram , variation (astronomy) , infrasound , rayleigh wave , ambient noise level , climatology , geodesy , oceanography , surface wave , acoustics , telecommunications , physics , sound (geography) , quantum mechanics , artificial intelligence , computer science , astrophysics , image (mathematics)
Very strong signals with apparent velocity higher than Rayleigh wave velocity are observed on noise correlation functions (NCFs) between seismic stations in East Asia. These signals are present on one‐month NCFs in ten years period with stable arrival times, indicating their persistent and localized nature. The signals are strong in the frequency band of 0.07–0.12Hz, and their amplitudes show inter‐annual but not seasonal variation. Location obtained from two algorithms with GSN and FNET data indicates that the source is situated in Kyushu Island, Japan. After an earthquake is used to account for heterogeneity effects, the location is closer to the Ariake bay but still in the island. The non‐seasonal amplitude variation and the peak frequency of 0.1Hz suggest the signals are probably not generated by oceanic sources. This persistent localized microseismic source needs to be taken into consideration in ambient noise tomography studies in East Asia.