晚更新世末期仙女山断裂带和天阳坪断裂带活动的最新证据

SEISMICITY ANOMALY IN SOUTH SHANDONG PROVINCE AND M L5.6 CANGSHAN EARTHQUAKE

依据野外槽探实测的仙女山断裂带和天阳坪断裂带的地质剖面，通过研究断层堆积与构造岩、新老构造岩变形、断层破裂及其几何特征、断层充填物采样年代鉴定等，获得了两断裂带晚更新世末期活动和古地震的最新证据。结果表明：天阳坪断裂带南支在１８２００±１２００年至１６９０±７６０年之间曾发生２～４次中强震，仙女山断裂带中段（都镇湾断裂）在２９０００±１３００年至大约１万年之间曾发生４次中强震。

The seismicity anomaly in south Shandong province is analysed by using the methods in the Guide for methods and forms of analysis and prediction of seismology .It is found that the M L≥2.5 earthquakes not occur since 23 months in south Shandong province before M L5.6 Cangshan earthquake,the M L≥3.0 earthquakes are concentrated mainly on the triangular zone among Xintai,Cangshan and Luxian after M L4.1 Xintai earthquake in June,1985, and the M L≥3.0 earthquakes along the Cangni fault since 1974 occur nearby the epicenter of earthquake of 5.6 magnitude. An obvious accelerated process of seismic strain energy release arises since 1988,the b value,seismicity S value and the absent earthquake curves of maximum magnitude show the low value anomaly.