地震活动多标度分形特征及预报应用

Characteristic and Application of Seismicity Multi-fractal

探讨了多标度分形在刻划复杂系统方面的优越性,研究了江苏及邻区1970年以来的5.5级以上地震的多标度分形特征,着重研究了地震前后多标度分形的广义维数谱和奇异性谱。研究结果表明:所有震例的广义维数谱和奇异性谱均经历了远离地震时、异常出现时和异常消失时的三个特征变化阶段;异常出现的时间在震前半年至一年半内;多数震例异常在震前几个月内回返恢复,少数在震后数个月内恢复。上述结果说明利用地震时序的多标度分形特征对于该地区的半年至一年尺度的中强地震预报是有意义的。

In this paper, the multi-fractal superiority in describing complex system is discussed ,and the multi-fractal characteristic of small earthquake time sequence for four earthquake examples （Ms≥5.5） since 1970 in Jiangsu province and the adjacent area are studied. It is indicated that the generalized fractal dimension spectrum and singularity spectrum of all examples have three variation stages which separately corresponding to the time far before earthquake, the time when ahnormity appeared and the time when abnormity disappeared; that the time when abnormity appeared is one year to one and half year before earthquake; that the abnormity came back several months before earthquake for most examples and several months after earthquake for one example. The result above shows that it is significant to apply the multi-fractal characteristic in mid-strong earthquake prediction of one year to one and half year scale in this area.