【摘要】 本文采用异常系列分析法研究了西北地区中强地震前后一定范围内水化异常群体随时间的演化特征。结果表明:地震前后水化异常频次累加曲线变化特征可归结成一种最基本的图象,即表现为;平稳—加速(增长)—恢复三个阶段的变化过程。地震与异常的关系表现为加速(增长)—地震的形式。而且对于不同地震及不同时间尺度(半年、月、旬)上,这种基本前兆图象具有较好地重现性。并且利用变化速率法和异常频次累加法对水化前兆图象变化的时间特征进行了定量描述和统计,给出利用这两种方法预测发震时间的范围。同时根据异常点空间分布特征和异常频次与震中距和震级的关系,统计并给出西北地区中强地震发生地点和震级的预测标志。更多还原

【Abstract】 Using the analytical method of anomaly series, we studied the evolutional characteristics of the hydrochemical anomaly group with time within a certain range before and after the moderate and strong earthquakes in the Northwest China region. The results show that the hydrochemical anomaly frequency accumulation curve before and after the earthquake exhibits three-period process: stable-accelerating ( increasing) -recovering. The changes of anomaly show a relation between accelerating (increasing ) and earthquake occurrence. This basic precursor pattern has a better recurrence to different earthquake magnitude and time scale (half a year, a month, ten days) . Using changing-velocity method anomaly frequency accumulation method, we also quantitatively described and counted the characteristics of hydrochemical precursor pattern and gave a time range of earthquake prediction. We provided prediction mark for occurrence location and magnitude of moderate and strong earthquakes in Northwest region according to the spatial distribution of anomalies and the relation between the anomaly frequency and the epicentra distance as well as the magnitude.更多还原