Earth Planets Space, Vol. 55 (No. 4), pp. e5-e8, 2003E-LETTER
Kimiyuki Asano, Tomotaka Iwata, and Kojiro Irikura
Disaster Prevention Research Institute, Kyoto University, Kyoto 611-0011, Japan
(Received February 4, 2003, Revised March 25, 2003 Accepted March 31, 2003)
Source modeling of recent shallow intraslab earthquakes is studied using strong-motion data. The total area of strong-motion generation areas obtained is smaller than the prediction from the empirical relationship for inland crustal earthquakes by Somerville and co-workers. Moreover, the ratio between the combined area of strong-motion generation areas obtained in this study and the area predicted by the empirical relationship, tends to decrease with focal depth. The stress drops on strong motion generation areas (or asperities) of shallow intraslab earthquakes increase with focal depth.
Key words: Shallow intraslab earthquake, strong-motion generation, empirical Green's function method, stress drop.