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Characteristics of short period secondary microseisms (SPSM) in Taiwan: The influence of shallow ocean strait on SPSM
Author(s) -
Chen YingNien,
Gung Yuancheng,
You ShueiHuei,
Hung ShuHuei,
Chiao LingYun,
Huang TzuYing,
Chen YenLing,
Liang WenTzong,
Jan Sen
Publication year - 2011
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 - 10.1029/2010gl046290
Subject(s) - seismometer , microseism , submarine pipeline , bathymetry , geology , range (aeronautics) , period (music) , seismology , oceanography , wind wave , acoustics , materials science , physics , composite material
Taking advantage of a unique opportunity provided by a dense array of coastal short‐period seismic stations and the diverse bathymetry around Taiwan, we examine how the long‐range coherent ambient noises are influenced by surrounding ocean settings using the cross‐correlation functions (CCFs) between pairs of stations. The effective energy of the CCFs derived from three components of short‐period seismometer data falls within the frequency range of the short period secondary microseism (SPSM). The spatial variations mapped from the amplitude asymmetry of CCFs and source migration images evidently demonstrate that the SPSM strengths are closely linked to the drastic changes in offshore ocean characteristics and result in much stronger SPSM in the shallow and narrow Taiwan Strait than in deep open seas of eastern Taiwan. The temporal variations of the CCF strengths exhibit very good correlations with the wind speeds and wave heights, explicitly indicating the observed SPSM is dominated by local sources generated from wind‐driven ocean waves around offshore Taiwan.