上海及邻区的地壳形变速率与地震活动

The crustal deformation rate and seismic activity in and around Shanghai

对上海佘山地震台伸缩仪的数字记录资料进行去趋势以及地壳形变速率的分析表明 :伸缩仪EW向在 2 0 0 1年 5～ 7月存在破年变趋势异常 ,并且该测项的形变速率在2 0 0 1年 3～ 8月存在高于正常背景值的异常。结合GPS资料、应力场、地震活动性的情况分析后认为 ,佘山台的形变速率异常可反映上海及邻区应力场的部分信息 ,该信息对地震活动具有一定前兆意义。因此 ,应用形变数字化资料计算地壳形变速率 ,可作为对地震活动以及日常地震预测的一种分析方法。

In this paper, based on the trend analysis of the digital tensometer data of the Sheshan Seismic Station of Shanghai,the crustal deformation rate is computed. The result shows that there is anomaly breaking the annual trend of tensometer data in the EW direction from May to July in 2001, and there is anomaly above the background value in the deformation rate of this measuring item from March to August in 2001. By the comprehensive analysis with GPS data,stress field and seismic activity, we can conclude that the deformation rate anomaly of the Sheshan Station may include some information about the stress field in and around Shanghai, this information has some precursor meaning of the seismic activity.So,using the digital deformation data to calculate the crustal deformation rate can be taken as a seismic method in the routine seismic prediction.