东北地震活动性短期预报方法研究

Study on the short-term prediction method of seismicity in Northeast China

研究了1970年以来东北地区发生的MS≥5·0浅源地震孕育过程中地震活动性参数和地震活动图像的变化特征,并对地震活动性参数进行了比较系统地综合预报效能评价,结果显示:东北9次(组)浅震地震前,所研究的5项地震活动性参数中,88·9%出现了持续3个月以上的短期异常变化,且5项参数R值评分结果都满足97·5%的置信水平;88·9%地震前震源区附近出现了孕震空区,有87·5%孕震空区在空区边缘或空区内部出现了ML≥4·0逼近地震,逼近地震以单个或成对的形式出现。66·7%的地震在震源区附近出现了地震条带异常。最后给出东北地区中强震的短期预报方法,这对未来东北地区的地震预报工作将起着一定的参考意义。

In this paper, the characteristics variation of seismicity parameters and seismicity patterns of shallow source earthquakes of Ms≥5.0 occurred in the Northeast China since 1970 are studied,and the prediction efficiency evaluation of seismicity parameters is also studied. The result indicates that of shallow source earthquake groups, about 88.9% of all occurred shortterm anomalous variation in 5 types of seismicity parameters and continued for three months, while the R value prediction evaluation reaches the confidence level of 97. 5% in 5 parameters, and 88. 9% of all occurred pregnant empty districts near the focus region before the main earthquakes. Among them, there were 87.5%empty districts that approaching earthquakes of ML≥4.0 occurred in the verge or inside the empty districts. The impending earthquake occurred by single or conjugated distribution. The number of earthquakes with which anomaly strip occurred near the focus region before shock is 66.7% of the total. Finally, a method for the short-term forecast of moderate and strong earthquake in Northeast China is presented. It is useful for reference to the earthquake prediction of the Northeast China in the future.