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Surface waves of the 2011 Tohoku earthquake: Observations of Taiwan's dense high‐rate GPS network
Author(s) -
Hung HuangKai,
Rau RueyJuin
Publication year - 2013
Publication title -
journal of geophysical research: solid earth
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.983
H-Index - 232
eISSN - 2169-9356
pISSN - 2169-9313
DOI - 10.1029/2012jb009689
Subject(s) - global positioning system , sidereal time , geodesy , seismometer , geology , seismology , precise point positioning , multipath propagation , broadband , gps signals , remote sensing , assisted gps , telecommunications , computer science , physics , gnss applications , channel (broadcasting) , astrophysics
Surface waves generated by the 2011 M w 9.0 Tohoku, Japan earthquake were recorded by both the high‐rate GPS and broadband seismic stations in Taiwan. In this study, we investigate the precision of high‐rate GPS displacements and estimate the feasibility of using GPS for seismology study in Taiwan. One hertz observations of 210 continuous GPS stations in Taiwan and neighboring islands were processed using a precise point positioning technique to estimate the absolute epoch‐by‐epoch positions generated by the Tohoku earthquake. Modified sidereal filtering was used to correct for near‐daily periodical variations of high‐rate position time series that may be influenced by multipath effects, and a band‐pass filter was used to remove noises from marginal frequencies. For all the 210 stations, the GPS precision after modified sidereal filtering improved from 8.2 to 7.4 mm in the horizontal and from 19.5 to 12.7 mm in the vertical components except for about 20% of the data with large position errors. After applying the band‐pass filter in the teleseismic frequency band (0.008–0.08 Hz), excluding 54 stations with noisy data, 156 continuous GPS stations were selected. Surface wave displacements derived from both high‐rate GPS and broadband seismometers are highly consistent, and the correlation coefficients are enhanced by a band‐pass filter (0.008–0.08 Hz) from 0.85 to 0.95 in the horizontal and from 0.58 to 0.85 in the vertical components. We consider continuous GPS can be used as an alternative approach to study characteristics of surface wave propagation in Taiwan.