Interseismic deformation at the Nankai subduction zone and the Median Tectonic Line, southwest Japan

Publication Status is "Submitted" Or "In Press: 
Yes
LDEO Publication: 
Yes
Publication Type: 
Year of Publication: 
2003
Editor: 
Journal Title: 
Journal of Geophysical Research-Solid Earth
Journal Date: 
Oct 11
Place Published: 
Tertiary Title: 
Volume: 
108
Issue: 
B10
Pages: 
-
Section / Start page: 
Publisher: 
ISBN Number: 
0148-0227
ISSN Number: 
Edition: 
Short Title: 
Accession Number: 
ISI:000185931300001
LDEO Publication Number: 
6484
Call Number: 
Abstract: 

[1] GPS velocities in the vicinity of the Nankai Trough, southwest Japan, were inverted into three components: interplate loading due to Nankai Trough subduction, deformation associated with deep slip on the Median Tectonic Line (MTL), and the residual rigid plate motion. The results show a gradual decrease of interplate seismic coupling between 25 and 40 km depth on the Nankai Trough interface. This is consistent with the deep slip model, in which the fault extends as a ductile shear zone, with a depth-variable interplate strain accumulation rate. The top 20 km of the interface may not be fully coupled, although the resolution is poor there. The low coupling at shallow depths is consistent with the accretionary prism detected by seismic surveys. The MTL slip rate is estimated to be between 0.00 and 5.50 mm/yr if we assume a vertical fault and between 0.00 and 3.88 mm/yr if we assume a north dipping fault. Combining our results with a geological estimate (4-9 mm/yr) and a geodetic estimate with a denser network (similar to5 mm/yr) suggests that the MTL slip rate may be near the upper bound of our geodetic estimate, that is, similar to4-5 mm/yr. The rigid plate motion with respect to the stable Eurasian craton was estimated to be very small, indicating that southwestern Japan is on the Eurasian plate rather than a separate plate.

Notes: 

732FZTimes Cited:2Cited References Count:45

DOI: 
Doi 10.1029/2003jb002441