MODELING OF FAULT RUPTURING OF SUBDUCTION PLATEBOUNDARY EARTHQUAKES WITH MAGNITUDE 9 FOR PREDICTING STRONG MOTIONS

-Application to the Nankai trough and examples of strong motions predicted in Tokai region-

Abstract

The feature of great subduction plate-boundary earthquakes such as the 2011 off the Pacifi c coast of Tohoku, Japan, earthquake (M_W 9.0) and the 2004 Sumatra earthquake (M_W 9.1) is that the short-period motions were generated on the deeper part of the fault and the long-period motions on the shallower part. Hence, we compiled the fault parameters of past subduction earthquakes and showed their scaling laws. Then, we proposed a procedure for making a consistent fault model both for the deeper part and the shallower part, applied our new procedure to the large subduction earthquake (M_W 9.1) along the Nankai trough off the Pacifi c coast of the West Japan, and showed four examples of the fault models including several asperities. Based on the four examples, we simulated ground motions in and around Nagoya City by the empirical Green's function method, and compared the seismic intensities of the simulated motions with those in the past three Nankai trough earthquakes.