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The 2003 M8.0 Tokachi‐Oki earthquake – How much has the great event paid back slip debts?
Author(s) -
Miura Satoshi,
Suwa Yoko,
Hasegawa Akira,
Nishimura Takuya
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 - 10.1029/2003gl019021
Subject(s) - slip (aerodynamics) , epicenter , geology , seismology , episodic tremor and slip , geodesy , subduction , tectonics , physics , thermodynamics
A great earthquake with M8.0 (the 2003 Tokachi‐Oki earthquake) occurred on September 26, 2003, on the plate boundary south of Hokkaido, at about the same epicenter as that of the 1952 M8.2 Tokachi‐Oki earthquake. We estimated the coseismic slip‐distribution using GPS data to obtain consistent results with that inferred from waveform inversions; a maximum slip larger than 5m exists around 30km NNE from the epicenter. Though the slip‐deficit estimated there (80 mm/yr) by our recent study is based on a rather short period of observation (5 years) to discuss the whole seismic cycle, the maximum coseismic slip roughly accounts for the slip‐deficit accumulated in the past 51 years, assuming that the back‐slip rate has been nearly constant since 1952. Besides the area of the largest slip, however, an accumulated slip‐deficit still remains and should be released by seismic or aseismic slip, which is now actually observed in part as postseismic slip.