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Detection of a slow slip event from small signal in GPS data
Author(s) -
Sato Tamao,
Imanishi Kazutoshi,
Kato Naoyuki,
Sagiya Takeshi
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 - 10.1029/2004gl019514
Subject(s) - seismology , geology , slip (aerodynamics) , seismic moment , episodic tremor and slip , asperity (geotechnical engineering) , intraplate earthquake , seismic gap , global positioning system , slow earthquake , induced seismicity , interplate earthquake , subduction , geodesy , fault (geology) , tectonics , geotechnical engineering , telecommunications , physics , computer science , thermodynamics
By correcting for seasonal noise contained in GPS data, we are able to detect small but compelling post‐seismic deformation following a medium‐sized interplate earthquake (2001 August 14, M W 6.4) that occurred off the Pacific coast of northern Honshu, Japan. Its decaying‐time constants are similar among the stations with an average of 2.2 months. We inverted for the slip distribution, assuming that post‐seismic deformation was due to a slow slip near the main shock fault. Slow slip spreads mainly over the northern periphery of the northern asperity of the 1968 Tokachi‐Oki earthquake (M W 8.2) that has been considered a seismic gap since 1994. The seismic moment of the slow slip is about three times greater (M W 6.7) than that of the co‐seismic slip. The present case suggests that the post‐seismic slow‐slip is common not only for the large earthquakes but also for relatively small interplate earthquakes in this region.