从强震前中强地震活动探讨川滇菱形块体内未来强震的可能性

Probing into the probability of future strong earthquake in Sichuan and Yunnan provinces from the present age character of medium-strong earthquakes stiuations

对中国西部南北地震带及相邻地区 ,190 0年以来 19次强震震前的中强地震活动图像进行了分析。结果表明 :9个震例显示 ,强震前在震中地区往往有早期地震和临震前的较大地震活动 ,而且早期地震至临震前较大地震活动的间隔时间与较大地震至主震时间有一个线性比值关系。通过给出的计算公式 :M =5 8+1 30 8logT(a) ,结合未来强震地区近期出现的中强地震事件的特定指标 ,预测研究区内未来强震可能发生的时间、地点和震级。

The active seismic images before the 19 strong earthquakes since 1970 occurred in onrth south seismic belts of western China and nearby regions are analyzed.Among our 19 strong earthquake cases,there are a lot of medium earthquakes happened near the epicenter areas before 9 strong earthquakes.These medium earthquakes can be divided into early period type earthquakes and impending type earthquakes.The interval between the early period earthquakes and the impending earthquake is a linear relationship with the interval between relative strong earthquakes and main strong earthquakes.Based on both formula M= 5.8+1.308×logT and special seimic indexes for medium strong earthquakes to happen in short period near the area of a strong earthquake,we try to forecast the position,magnitude and time of strong earthquake in the research area.