中国大陆7级大震序列时间特征及中期预测方法

TIME FEATURES OF LARGE EARTHQUAKES WITH M≥7 AND THE MEDIUM-TERM EARTHQUAKE PREDICTION IN CHINA

本文基于1897年以来我国大陆地区7级大震实际观测序列,对7级大震的时间分布特征进行了较系统的分析与研究,并针对不同时期地震活动在时间轴上分布不均匀的特点,引入了地震危险随时间增长的加权韦布尔中期预测方法。结果表明:中国大陆7级大震序列是一个准泊松过程,大震连发是造成该序列具有非均匀特性及其它现象的一个重要影响因素;加权韦布尔中期预测方法有效性检验结果显示出,加权地震危险性计算结果较好地反映了实际地震的非均匀发生过程。本文所得结论对我国大陆地区7级大震形势估计可能会起一定的参考作用。

By using the large earthquake sequences with M≥7 occurred in the mainland of China since 1897, authors systematically discussed the temporal distribution of the seismicity. The medium-term method of earthquake prediction based on the Weibull model with the weight is put forward in accordance with the ununiform distribution of the events along the time axis. The results show that the sequence of large earthquakes in an apparent Poisson process and the occurrence of swarms has an important effect on the earthquake sequence. The test result reveals that the method with the weight is more efficient than that without the weight. The conclusion drawn in this paper may be useful to the tendency estimation of large earthquakes in the future in the mainland of China.