【摘要】 为探索大地震发生的可预测性，应用分形理论并根据标准数盒子的数值计算方法，研究了华北地区历史地震和唐山地区地震活动的空间分布特征，估算了地震活动能量的分维值并研究了其多重分形谱的几何结构．初步结果显示出大地震发生前，广义维值有明显的下降过程，分形谱ｆ（α）结构有右偏现象．在低于上述时空层次的唐山地区，孕震系统也有类似特征出现．这些异常现象揭示出孕震动力系统的物理机理和激变前的某些不稳定性．更多还原

【Abstract】 In order to explore the predictability of earthquakes, the distributioncharacteristics of seismic activity in time and space for Huabei and Tangshan area arestudied by multifractal theory and box-counting method. The generalized dimensionsD(q) of seismic achvity energy are estimated, and the geometry structure of theirmultifractal spectrum is also analyzed. The results show that the values of thegeneralized dimensions are obviously low, and there is a low value process before thelarge earthquake occurrence and the f(α) spectrum is partial to right. A similarcharacteristic is found in Tangshan area. The anomalous phenamena revealed thephysical essence and some instability before interior crisis of seismogenic system.更多还原