新疆地区强震前中短期阶段地震活动异常动态图像

DYNAMIC PATTERNS OF SEISMICITY ANOMALIES IN MEDIUM,SHORT TERM BEFORE STRONG EARTHQUAKES IN XINJIANG

利用２ 个描述强震前中短期阶段地震活动异常平静及丛集的参量，计算了新疆地震区１９７０～１９９８ 年以１ 年为窗长、３ 个月为步长的地震活动异常图像，并给出了发生在新疆乌恰的２ 次７．４ 级地震前后，新疆地区σＮ 异常分布动态演化图像。对异常图像的动态演化过程与强震发生地点的关系进行了分析；对将其用于新疆地区地震预测进行了预测检验。结果表明：该参量能较好和直观地描述中强震前地震活动异常时空动态图像，不受样本量的限制，并能给出未来发生强震的可能地区。该方法在预测新疆发生强震危险区方面有较好的效果。

Two parameters, σ N and σ E,depicting the calming and clustering of seismicity anomalies in medium and short term before strong earthquakes are calculated in Xinjiang earthquake regions from 1970～1998(the window length is 1 year and the step length is 3 months).Based on this result the dynamic patterns of σ N anomaly evolution before and after two M S 7.4 earthquakes in Wuqia,Xinjiang are drawn.The research shows:the parameter σ N can depict dynamic time space patterns of seismicity anomalies better and directly;not only is it not limited by the number of samples but also it is able to give the capable locations of future strong earthquakes,so it's a better method to predict risk region of strong earthquakes in Xinjiang.