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Modeling the rupture process of the 2003 September 25 Tokachi‐Oki (Hokkaido) earthquake using 1‐Hz GPS data
Author(s) -
Miyazaki Shin'ichi,
Larson Kristine M.,
Choi Kyuhong,
Hikima Kazuhito,
Koketsu Kazuki,
Bodin Paul,
Haase Jennifer,
Emore Gordon,
Yamagiwa Atsushi
Publication year - 2004
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 - 10.1029/2004gl021457
Subject(s) - global positioning system , geology , seismology , hypocenter , geodesy , slip (aerodynamics) , subduction , waveform , seismic moment , fault (geology) , induced seismicity , tectonics , computer science , telecommunications , radar , physics , thermodynamics
High‐rate GPS has the potential to recover both dynamic and static displacements accurately. We analyze 1‐Hz GPS data recorded during the 2003 Tokachi‐Oki earthquake. The 1‐Hz GPS displacement waveforms show good agreement with integrated accelerometer records except for low frequency noise that are inherently present in integrated seismic records. The GPS waveforms were inverted to model the spatio‐temporal evolution of the fault slip during the rupture. The slip is found to propagate downdip in the subduction zone with largest moment release ∼50 km northwest of the hypocenter. The region of largest slip agrees in general with traditional seismic studies, indicating that 1‐Hz GPS can be used for finite fault studies. The 1‐Hz GPS slip model shows clearer contrast with afterslip distributions than those inferred from strong motion data, possibly because 1‐Hz GPS is more sensitive to cumulative slip distribution.