1990年景泰6．2级地震前后甘肃东南部地区的区域异常──地震前兆与后效区分  

THE REGIONAL ANOMALIES IN THE SOUTHEAST OF GANSU PROVINCE BEFORE AND AFTER TBE JINGTAI Ms 6. 2 EARTHQUAKE IN 1990 ──Preliminary Research on the Problem of Distinguishing between the Precursor and Postseismic Erfect

作　　者：毛可[1] 郭大庆[1] 李秦梅[1] 张慧[1] 郑田新[1] 郭文娣 

机构地区：[1]国家地震局兰州地震研究所,国家地震局分析预报中心

出　　处：《西北地震学报》1996年第1期8-15,共8页Northwestern Seismological Journal

摘　　要：在分析地震活动性、地壳形变和其它前兆资料基础上指出，１９９０年景泰６．２级地震前后甘肃东南部地区的区域异常具有变化速率小，起始时间不同步，异常反映的力学性质不一致等特征，其中以异常变化速率小最为显著。该特征与地壳形变及地震活动性异常变化有较好的一致性。通过分析，认为景泰６．２级地震前甘肃东南部地区出现的群体异常是共和７．０级地震和景泰６．２级地震的区域性前兆，震后该区持续的异常变化反映了强震后大范围内的应力调整过程。甘肃东南部地区构造环境特殊，该地区可能是南北地震带第５、第６强震组的共同调整区之一。In this paper, based on the analysis of seismicity, crustal deformation and other precursory data, the authors indicated that the regional anomalies in the southeast of Gansu Province before and after the Jingtai Ms 6. 2 earthquake in 1990 are characterized by small changing speed,a synchronous start time,different mechanics natures reflected by different anomalies,and so on. These accord with the anomalous changes of crustal deformation and seismicity. It is considered that the group anomalies in the southeast of Gansu before the Jingtai Ms 6. 2 earthquake are regional precursor of the Gonghe Ms 7. 0 and Jingtai Ms6. 2 earthquakes. The sustained anomalies after the earthquake reflected the stress adjustment within a vast area.The structure conditions in the Southeast of Gansu have their specific characters. The southeast of Gansu likely is one of the common adjusting regions of the sib and the 6th strong earthquake clusters along the North-South earthquake zone.

关 键 词：地震前兆 震后效应 景泰地震 区域异常 

分 类 号：P315.7[天文地球—地震学]