Interseismic uplift at the Nankai subduction zone, southwest Japan, 1951–1990

Journal of Geophysical Research B: Solid Earth
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Abstract

Uplift as a function of time from 1951 through 1990 has been deduced from annual mean sea level measured at 15 tide gages along the Nankai subduction zone, southwest Japan. The recurrence interval for rupture of the Nankai subduction zone is about 100 years, and the most recent rupture was in late 1946. Thus the 1951–1990 uplift record covers most of the first half of the earthquake cycle. The precision of the uplift record is better than could be obtained currently by annual Global Positioning System (GPS) measurements. The pre‐1960 uplift record shows rapid deformation that appears to terminate in 1959. After 1959 the uplift record is remarkably linear in time: Significant curvature in the uplift‐versus‐time plots is detected at only three of the 15 tide gages. The inferred uplift rates are not quantitatively consistent with the predictions of either the viscoelastic coupling or elastic half‐space models of subduction, but the agreement is sufficient to suggest that the causative physical mechanisms have been identified. The immediate postseismic response is controlled by the propagation of slip downward along the downdip extension of the coseismic rupture, and the interseismic response is caused by the accumulation of a slip deficit on the main thrust zone. Asthenosphere relaxation is not required to explain the observations.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Interseismic uplift at the Nankai subduction zone, southwest Japan, 1951–1990
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1029/95JB00242
Volume 100
Issue B4
Year Published 1995
Language English
Publisher American Geophysical Union
Contributing office(s) Earthquake Science Center
Description 12 p.
First page 6339
Last page 6350
Country Japan
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