【摘要】 以山西前兆观测的８大观测项目为基础，研究１１９８９年以来，山西地震带发生的３次中强地震前前兆异常的频度、密度、持续时间以及空间分布特征，结果表明：趋势异常的频次与震级大小成正比；２次大同地震前异常表现出不同的特点，实用化攻关方法对异常的处理判别指标显示出震前具有减熵、有序度增高、综合积分超过本区预报分数线等特征。更多还原

【Abstract】 Based on 8 procursor monitoring approaches in Shansi province,the frequency, denity,duration time andspatial distribution feature of the precursor anomalies before 3 moderate earthquakes in Shanxi since 1989have been studied. The conclusion is that the frequency of trend anomalies is directly proportional to theearthquake magnitude,the anomalies before 2 earthquakes in Datong-yanggao show different features,and theanomaly discreminant indexes obtained with the method of the Key Task of the Application are characterizedby entropy decreasing,order degree increasing and synthetic accumulative grades exceeded the prediction in-dex of this area.更多还原