强震前后广义地震应变释放过程的丛集特征

Research on the clustering of generalized seismic strain release process before and after strong earthquake occurrence

利用基于小波变换的多重分形奇异谱估计方法,研究了部分强震前后地震活动广义应变释放过程的多重分形特征。结果表明,震中区附近一定范围内地震活动广义应变释放过程具有多重分形特征,但多重分形维数谱随η变化复杂,在强震发生前多重分形维数谱没有明显的变化。广义地震应变释放过程的多重分形奇异谱形态和Hausdorff奇异指数范围能提供更多关于地震活动过程的信息,特别当η取较大值时Hausdorff奇异指数范围在强震前明显变窄。研究还表明深源地震和浅源地震发生前广义应变释放过程多重分形特征存在明显不同。

By using the wavelet transition-based multifractal spectrum estimation method, the multifractal characteristics of generalized seismic strain release process before and after strong earthquake occurrence have been discussed. The results show that the multifractal dimension spectrum varies seriously with the changes of the parameter.It is also found that the multi-fractal dimension spectrum doesn't change obviously before and after strong earthquake occurrence. The multifractal singular spectrum and the range of Hausdorff singular index could provide more information on seismically active process, especially when the parameter is higher (e. g. larger than 1). The range of Hausdorff singular index is obviously going narrower before strong earthquake occurrence. Also, the multifractal characteristics of generalized seismic stress release process are apparently different for deep and shallow strong events.