A seismic risk evaluation in Korea.

A seismic risk map of Korea is constructed using the modified first asymptotic distribution of the extreme value theory (KIM, 1981). The seismic data of historical earthquakes (1405-1905) and instrumentally recorded earthquakes (1906-1981) are obtained from the ancient Korean documents and seismograph stations, respectively. The earthquake data of this study are shallow-focus earthquakes whose magnitudes are equal to or greater than 5.0.Maximum potential earthquakes that are expected to occur with a 10% exceeding probability within 30 years are estimated in 6 seismic provinces of the Korean Peninsula. Finite seismic sources of expected maximum potential earthquakes are assumed to be near the cell of the meizoseismal areas in each seismic province. Maximum ground accelerations or particle velocities for all points on a grid are computed using Kanai's equation and the results are contoured.