上海地区区域稳定性评价

APPRECIATION OF REGIONAL STABILITY OF SHANGHAI REGION

通过对上海地区重磁场特征、地质构造特征与地震震中的相关性分析，认为地震震中主要分布于重磁梯度带的叠加干扰部位正负重磁异常边缘、尤其是转折和凸起部位；在断裂构造上地震震中主要分布于具有一定活动性的北西、北东向断裂上，尤其是北东与北西向断裂的交会部位。根据以上规律，对上海地区的青浦，崇明，浦东地区的稳定性进行了定性分析。同时，应用定量分析方法对上海地区的区域稳定性进行了多元回归分析。结果表明，上海地区地震预测烈度在4—6之间，总体上属于基本稳定区，而且浦东地区稳定性最好，崇明地区次之，青浦地区稍差。

Through the correlation analysis of the characteristics of gravity-magnetic fields andgeological structures with the seismic epicenters, the author interprets that the seismic epicenters are mainly distributed in the stacking disturbing positions of gravity-magneticgradient belts,and in the positive and negative gravity-magnetic anomaly margins,especially in the hinge and convex positions. On the relations with fault structure, the seismic epicenters are mainly distributed in the NW and NE faults which have some activities, especially in the across positions of NW and NE faults. According to those regularities, thequalitative analysis of stability in the Qingpu, Chongming, and Pudong districts of Shanghai region have been workd out. Meanwhile, using the method of quantitative analysis, amultiple regression analysis of the regional stability in Shanghai region has been workedout. The result shows that the seismic intensity will be 4 to 6 magnitude, indicating overallit belong to a fundamental stable region, and among them the stability in the Pudong is thebest, and then is the Chongming, which is better than the Qingpu.