中国大陆地震震例异常统计与分析

Statistics and analyses of the anomalies of earthquake cases in China′s mainland

以1986～1999年中国大陆地震屣例为基础，对中国大陆及其不同分区的测震和前兆异常进行了统计与分析。研究结果认为：地震异常数目、异常站点和项次百分比随着震级的增大而增多；震级高异常出现的时间早，异常范围大；中期异常多于短期异常，短期异常多于临震异常，目前还缺少较多有效的观测到短临异常的方法。测震中的频度、空区、b值、缺震、条带、地震窗、前兆震（群）、地震活动分布、应变释放测项和前兆中的水化学、水物理、地形变、地电测项是出现较多的异常测项。不同的区域异常出现率高的测震和前兆测项不同，显示出区域差异。

Based on the earthquake cases in China＇s mainland from 1986 to 1999, this paper carries out statistics and analyses of the seismometry and precursory anomalies in China＇s mainland and its dissimilar suhareas. The results show that the numbers, stations and item-percentages of these anomalies increase with the growth of the magnitude. Anomalies appear earlier and their range is wider for stronger earthquakes. The mid-term anomalies are more than the short term anomalies; the short-term anomalies are more than the impending ones, recently we still lack some efficacious methods, which can catch the impending seismic earthqu than th earthquake anomalies. In seismometry anomalous items, earthquake frequency, gap, b value, earthquake deficiency, seismic stripe, seismic window, precursory akes （or swarms）, seismicity pattern and strain release appear more frequently e other items, in precursory anomalous items, hydrochemistry, hydrophysics, ground deformation, geoelctricity appear more frequently than the other items. In dissimilar areas the seismometry and precursory items that appear more frequently are different, which reveal the regional distinction.