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The potential for a great earthquake along the southernmost Ryukyu subduction zone
Author(s) -
Hsu YaJu,
Ando Masataka,
Yu ShuiBeih,
Simons Mark
Publication year - 2012
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 - 10.1029/2012gl052764
Subject(s) - subduction , geology , seismology , trench , episodic tremor and slip , slip (aerodynamics) , plate tectonics , pacific plate , tectonics , chemistry , physics , organic chemistry , layer (electronics) , thermodynamics
Interseismic GPS data along the Hualien‐Suao coast (NE Taiwan) shows a pattern of strain accumulation that is consistent with a potential future large shallow earthquake along the southernmost Ryukyu subduction zone. The measured shortening rate parallel to the Ryukyu Trench is 80 mm/yr, about twice of the shortening rate perpendicular to the Ryukyu Trench. We invert for slip‐deficit rates and the geometric configuration of the plate interface. Our preferred fault model dips 10° northward and extends about 70 km from the Ryukyu Trench to a depth of 13 km. The slip‐deficit rate exhibits a left‐lateral motion of 78 mm/yr and a normal motion of 36 mm/yr on a 290°‐trending fault. The slip rate budget of the southernmost Ryukyu subduction zone is close to the plate convergence rate, suggesting the plate interface is fully locked. Assessments of seismic hazard in this region need to consider the potential threat from M w 7.5∼8.7 tsunami earthquakes generated by shallow ruptures.