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The 1993 Kushiro‐Oki, Japan, Earthquake: A high stress‐drop event in a subducting slab
Author(s) -
Takeo Minoru,
Ide Satoshi,
Yoshida Yashuhiro
Publication year - 1993
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 - 10.1029/93gl02864
Subject(s) - geology , seismology , aftershock , slab , trench , slip (aerodynamics) , interplate earthquake , fault plane , subduction , stress field , seismic moment , intraplate earthquake , pacific plate , foreshock , fault (geology) , tectonics , geophysics , chemistry , physics , organic chemistry , layer (electronics) , finite element method , thermodynamics
A spatial slip distribution of the 1993 Kushiro‐Oki earthquake (M w ; 7.6) is undoubtedly constrained using near‐field data and the detailed aftershock distribution. This earthquake has peculiar features in that the slip on the fault plane is restricted within an extremely small area (about 40 km × 20 km) between the upper and lower planes of the double seismic zone in the subducting slab beneath Hokkaido. The total seismic moment, averaged slip, and stress‐drop in this area are 3.3 × 10 20 Nm, 5.5 m, and 4.2 × 10 7 Pa, respectively. This earthquake indicates that the region of the slab between the planes of the double seismic zone beneath Hokkaido is strong enough to sustain a stress of about 4 × 10 7 Pa. The slip motion of this event is consistent with retrograde slab migration along the Southern Kuril trench, and may represent a process by which retrograde motion of subducting slabs could occur.