山东地区及其海域近期地震活动特点

CHARACTERISTICS OF SEISMIC ACTIVITY ABOUT SHANDONG AND ITS SEA AREAS IN RECENT YEARS

本文通过对山东地区及其海域的历史地震（Ｍｓ≥５）和近代小震活动的分析，认为该区的历史地震活动，自１６８８年以来存在三个Ｍ≥５级地震活动空段（菏泽—临沂，聊城—惠民，渤海—威海）；而１９６０年以来，该区ＭＬ≥４．５级地震具有８年的活跃时间段的特点。并得出山东地区及其海域ＭＬ≥４．５级地震活动还将持续３年，从近期小震活动研究结果表明，渤海海域及其邻区存在空区和小震活动条带。并得出该区存在低ｂ值，应变释放加速等异常特点。

On the basis of the analysis of historical and recent seismic activity in Shandong and its sea areas we conclude the following results. Study area exists three active segments (M≥5) since 1968 (Heze-Linyi, Liaocheng-Huimin,Bohai-Weihai) .The area have active period of eight years since 1960 from which the seismic activity will last three years in Shandong and its sea area. According to the analysis of small earthquakes activity in recent years the areas exist seismic gaps and small earthquake belt from which low b values and strain release acceleration are obtained.