Earth Planets Space, Vol. 57 (No. 6), pp. 471-475, 2005
Sun-Cheon Park and Jim Mori
Disaster Prevention Research Institute, Kyoto University, Gokasho, Uji 611-0011, Japan
(Received November 20, 2004; Revised April 22, 2005; Accepted April 25, 2005)
A moderate earthquake with local magnitude 5.2 (ML ) occurred off the eastern coast of South Korea on May 29, 2004. This earthquake is one of the largest events near the Korean Peninsula since 1978 when instrumental observations began by the Korea Meteorological Administration. We carried out modeling of regional waveforms and deconvolutions using empirical Green functions to estimate source parameters. The results of the regional waveform modeling show a reverse fault mechanism with a hypocentral depth of 8 km and seismic moment of 5 × 1016 N · m, which is equivalent to Mw 5.1. Performing the empirical Green function deconvolution, we estimated a fault radius of 1.1 to 1.4 km and an average stress drop of 13.5 MPa, assuming an east dipping fault plane. Assuming a west dipping fault plane, we estimated a fault radius of 1.3 to 2.9 km and an average stress drop of 6.6 MPa.
Key words: Earthquake, waveform modeling, deconvolution, South Korea, empirical Green function.