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Interplate coupling along the Nankai Trough off southwest Japan derived from GPS measurements
Author(s) -
Ozawa Taku,
Tabei Takao,
Miyazaki Shinichi
Publication year - 1999
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 - 10.1029/1999gl900145
Subject(s) - subduction , geology , seismology , eurasian plate , coupling (piping) , plate tectonics , trough (economics) , slip (aerodynamics) , pacific plate , geodesy , tectonics , physics , materials science , metallurgy , macroeconomics , economics , thermodynamics
We investigate interplate coupling between the Philippine Sea and the Eurasian plates at the Nankai Trough off southwest Japan during the interseismic period. Plate coupling is modeled by imaginary backward normal slip superposed on the steady‐state subduction. We divide the plate interface into several segments, and estimate coupling on each segment from GPS horizontal velocity data. Estimated coupling is in general agreement with the rate of steady‐state subduction predicted from a plate motion model. This implies that current coupling at the Nankai Trough is so strong that much of the relative plate motion is taken up by shortening of the leading edge of the overriding plate. It seems that stronger interseismic coupling is realized on the segment where larger coseismic dislocation occurred, and vice versa. Time fluctuation of plate coupling from 1995 to 1996 is found on a small segment.