阳原4.8级和大同5.8级地震前兆异常的模糊识别及其特性分析

Fuzzy Recognition of Precursory Anomalies Before the Yangyuan of M4. 8 and the Datong of MS. 8 Earthquakes and the Analyses of Their Characteristics

利用模糊模式识别的直接方法提取了1988年河北阳原4.8级地震和1989年山西大同5.8级地震的多项前兆异常,取得了较好的效果。对这些异常的综合分析结果表明:阳原地震与大同地震是有联系的,两次地震前都有异常频次峰值出现,峰值出现后一个月左右发震;震中区位于前兆异常从属函数高异常区附近;震级较高的地震,其从属函数值也较大;前兆异常的空间优势分布位于高丽营—黄庄断裂和程各庄—夏垫断裂带上,对该地区未来的地震活动应予注意。

By using the direct method of fuzzy pattern recognition a lot of precursory anomalies before the 1988 Yangyuan (M=4. 8)earthquake in Hebei Province and the 1989 Datong (M=5. 8)earthquake in Shanxi Province have been distinguished more successfully.The results of synthetic analyses of these precursory anomalies show that the Yangyuan and Datong earthquakes were related to each other. Before both events the anomalous frequency appeared and reached to the peak values. and the occurrence time of events were just in about 1 month after the appearance of such peak values. The epicenter regions of these earthquakes were located near the areas where the values of membership function μ of precursory anomalies were relatively high. Moreover,the larger earthquake magnitude, the higher the μ-value was. The domain spatial distribution of precursory anomalies was concentrated along the Gaoliying-Huangzhuang Fault and the Chengezhuang-Xiadian Fault. Therefore, the forthcoming seismic activity in this region must be noticed.