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Tomography of northeast Japan forearc and its implications for interplate seismic coupling
Author(s) -
Mishra O. P.,
Zhao Dapeng,
Umino N.,
Hasegawa A.
Publication year - 2003
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 - 10.1029/2003gl017736
Subject(s) - forearc , geology , seismology , trench , intraplate earthquake , subduction , coupling (piping) , interplate earthquake , tectonics , mechanical engineering , chemistry , organic chemistry , engineering , layer (electronics)
We determined, for the first time, a 3‐D seismic structure of P and S wave velocity (Vp, Vs) in the forearc region of northeast (NE) Japan from the Pacific coast to the Japan Trench using a large number of high‐quality arrival times from sub‐oceanic earthquakes that are well located with sP depth phase data. Strong lateral heterogeneities in Vp and Vs are revealed. A majority (95%) of great interplate earthquakes are located outside the low‐V zones while a few (5%) of them are located inside the low‐V zones. This may suggest a different degree of interplate seismic coupling at the plate interface parallel to Japan Trench. The low‐V zones probably contain fluids and may represent decoupled areas. We propose that this new approach of investigating 3‐D seismic structure can be applied to other forearcs of the world for a better understanding of interplate coupling and its influence on big earthquakes.