Interplate seismogenic zones along the Kuril–Japan trench inferred from GPS data inversion

Stress accumulation between earthquakes results from slip that is insufficient to fully accommodate plate movement. An inverse analysis of GPS data from the Kuril–Japan trench reveals a trench-parallel belt of stress accumulation with six peaks in the depth range of 10–40 km, suggesting potential source regions for future earthquakes. In the subduction zones around Japan, where four plates interact with one another, large earthquakes have occurred repeatedly1. These interplate earthquakes are part of the process of tectonic stress accumulation and release that is driven by relative plate motion2,3,4. Stress accumulation between earthquakes results from slip deficit (slip that is insufficient to fully accommodate plate movement). For the prediction of large earthquakes, it is therefore important to monitor the distribution of slip deficit on plate interfaces. Here we apply an inversion method based on Bayesian modelling (using direct and indirect prior information on the magnitude and distribution of fault slip5) to horizontal and vertical velocities from global positioning system data. For the seismically calm period between 1996 and 2000, we obtain a precise distribution of slip-deficit rates on the interface between the North American and Pacific plates around Japan, which reveals a trench-parallel belt of slip deficit with six peaks in the depth range of 10–40 km. These peaks agree with the source regions of past large interplate earthquakes along the Kuril–Japan trench. We conclude that the slip-deficit zones identified with our method are potential source regions of large earthquakes.

[1]  E. Fukuyama,et al.  Simulation of the Transition of Earthquake Rupture from Quasi-static Growth to Dynamic Propagation , 2002 .

[2]  T. Sagiya,et al.  Continuous GPS Array and Present-day Crustal Deformation of Japan , 2000, pure and applied geophysics.

[3]  M. Matsu'ura,et al.  3-D Physical Modelling of Stress Accumulation Processes at Transcurrent Plate Boundaries , 2000 .

[4]  Masaya Matsuura,et al.  Geodetic data inversion using a Bayesian information criterion for spatial distribution of fault slip , 1992 .

[5]  M. Matsu'ura,et al.  Geodetic data inversion based on Bayesian formulation with direct and indirect prior information , 2007 .

[6]  Catarina I. Kiefe,et al.  Application of Statistics , 2000 .

[7]  Akira Hasegawa,et al.  Interplate coupling beneath NE Japan inferred from three-dimensional displacement field , 2006 .

[8]  Mitsuhiro Matsu'ura.  Quest for predictability of geodynamic processes through computer simulation , 2005, Computing in Science & Engineering.

[9]  Chihiro Hashimoto,et al.  3-D Modelling of Plate Interfaces and Numerical Simulation of Long-term Crustal Deformation in and around Japan , 2004 .

[10]  K. Satake,et al.  The tsunami source area of the 2003 Tokachi-oki earthquake estimated from tsunami travel times and its relationship to the 1952 Tokachi-oki earthquake , 2004 .

[11]  X. Pichon,et al.  Full interseismic locking of the Nankai and Japan‐west Kurile subduction zones: An analysis of uniform elastic strain accumulation in Japan constrained by permanent GPS , 2000 .

[12]  David D. Jackson,et al.  A Bayesian approach to nonlinear inversion , 1985 .

[13]  Richard G. Gordon,et al.  Effect of recent revisions to the geomagnetic reversal time scale on estimates of current plate motions , 1994 .

[14]  M. Matsu'ura,et al.  3-D Simulation of Earthquake Generation Cycles and Evolution of Fault Constitutitve Properties , 2002 .

[15]  K. Satake,et al.  Unusually large earthquakes inferred from tsunami deposits along the Kuril trench , 2003, Nature.

[16]  Yuji Yagi,et al.  Source rupture process of the 2003 Tokachi-oki earthquake determined by joint inversion of teleseismic body wave and strong ground motion data , 2004 .

[17]  S. Miyazaki,et al.  Interplate coupling in northeast Japan deduced from inversion analysis of GPS data , 2000 .

[18]  M. Kikuchi,et al.  Asperity map along the subduction zone in northeastern Japan inferred from regional seismic data , 2004 .

[19]  Tomowo Hirasawa,et al.  Temporal change of interplate coupling in northeastern Japan during 1995–2002 estimated from continuous GPS observations , 2004 .

[20]  Mitsuhiro Matsu'ura,et al.  A dislocation model for the earthquake cycle at convergent plate boundaries , 1989 .