STUDY OF THE CHARACTERISTICS OF SEISMIC ACTIVITIES ON LIAOKAO FAULT ZONE
LIU Kai;HAI Chang-hong;CHEN Yan-e;XIA Yan;Dezhou Seismic Station;
Liaokao fault zone is a boundary fault block between the liftup in West Shandong and the sunken in North China. Great geological differences on both sides bring about frequent seismic activities in this area.In the history, there are several earthquakes with magnitude larger than M5.0. Since the Quaternary Period, the most frequent seismic activities occurred in the southern part, less in the middle, and the least in the northern part. The epicenter distribution changes in order. In addition, seismic zone has changed since 1970. Before middle 1990s, seismic activities are mainly concentrated in Heze. Since the second half of 1997, seismic activities occurred mainly in Puyang-Juancheng area. The seismic reinforcement process has happened twice from now on.