Abstract: Information extraction and analysis about cross-fault deformation is one of the important contents in earthquake research. Based on the theory of wavelet analysis and information entropy,the wavelet multi-scale entropy that describes the ordering degree in local data has been proposed in this paper. We studied the wavelet multi-scale entropy variation characteristics before strong earthquakes and the relationship between decreasing entropy anomaly and the three elements of earthquake by using the cross-fault fixed deformation data from Tianshan area in Xinjiang. The results indicate that:the amount of information of high frequency component is more than that of low frequency in cross-fault deformation rate,and a decreasing entropy anomaly appears before most of strong earthquakes. Furthermore,the logarithm of cumulative decreasing entropy is obviously linear with magnitude and the time from the beginning of anomaly to the occurrence of earthquake. If the magnitude is larger,the time from the beginning of anomaly to earthquake will be longer,and the cumulative decreasing entropy will be larger. Finally,the association is obvious between the integral decreasing entropy of multiple stations and large range crustal movement and the seismic active period.

Key words: fault deformation, wavelet analysis, multi-scale entropy, earthquake anomaly, Xinjiang

摘要： 跨断层形变资料的信息提取与分析是地震研究的重要内容之一。文中以小波分析和信息熵理论为基础,提出了能够反映局部数据信息有序度大小的小波多尺度熵信息提取方法。研究了新疆天山地区跨断层定点形变观测资料强震前小波多尺度熵的变化特征,并应用多元线性回归方法分析了减熵异常与地震三要素之间的关系。结果表明:跨断层形变速率的相对高频成分携带的信息量大于中低频成分,大多数强震前小波多尺度熵有低值异常出现,累计减熵量的对数与震级、异常起始至发震的时间具有显著的线性关系,表现为震级越大,异常起始至发震的时间越长,累计减熵量越大,多个测点整体熵值的减少与大范围的地壳运动及地震活跃期存在一定程度的关联性。

关键词: 断层形变, 小波分析, 多尺度熵, 异常, 新疆