强震前地震非均匀度异常与前兆群体异常关系的研究

Study on correlation between anomalies of seismic inhomogeneous degree and that of group precursory before strong earthquakes

通过对比研究华北地区部分中强以上地震震前地震非均匀度异常与区域地震前兆观测群体异常的变化过程,发现两者在地震前的异常时空演化过程中,具有一定的关联性。在时间上,部分地震震前的地震非均匀度异常出现后,半年左右前兆观测异常在数量上将出现一次较大幅度的增加;在空间上,前兆异常展布范围与地震非均匀度异常范围大体一致。研究结果表明,地震非均匀度(GL值)在强地震前出现的异常变化从震例的角度,表明可能与局部应力场变化有关。地震非均匀度和前兆群体异常的这种准同步变化,可能对判定地震孕育进入中短期阶段具有一定的指示意义。

It is found that there is a certain correlation between the anomaly of the seismic inhomogeneous degree and that of the group precursors before strong earthquakes during the evolution process of the anomalies in both time and space based on the comparison. That is to say, the amount of the of precursory anomaly increases suddenly about 8 months prior to the appearance of the seismic inhomogeneous degree appears before strong earthquakes in time, and the distribution areas of the two types of the anomalies are consistent approximately. The result shows that anomalous variation of the seismic inhomogeneous degree may be related to the change of the regional stress from the view of earthquake cases. The consistently anomaly variation of the seismic inhomogeneous degree and the group precursory anomaly may be the clew to the judgment of the middle-term and short-term earthquake prediction.