形变台点异常事件与强震活动关系的研究

RESEARCH ON RELATIONSHIP BETWEEN DEFORMATION ANOMALIES MEASURED AT STATIONS OR SITES AND STRONG EARTHQUAKE ACTIVITIES

摘要:

收集了我国大部分跨断层流动测量和跨断层形变台站资料,统计了阶跃、突跳、趋势转折和年变规律改变等异常变化,并与相应区域内M_S≥6.0以上地震的时空分布进行了对比分析,结果认为:(1)突出的台点形变异常和强震活动在上一个强震活动高潮期均存在由西南向华北往复迁移的特征;(2)突出的台点形变异常峰值期与强震活动高潮期存在一定的对应关系;(3)1987年以来形变异常和强震活动由西南向华北迁移的特征不明显,但地震活动在南北带上往复迁移的特征仍然存在;(4)未来一段时间内,华北发生M_S6.0以上强震的可能性不大,而南北带的北部不能排除。

关键词:形变异常;地震;跨断层测量

Abstract:

Most of the crass-fault deformation data measured at fixed stations and mobile sites in China are collected, the obvious anomaly variations of it such as stepping, pulse, tendency change and anniversary rule change are searched, and the comparison analysis between the anomalies and earthquakes with M_S≥6.0 in the same area is made to find their distribution regulation both in time and space. The results show:(1)Both of the anomalies and strong earthquakes migrate to and fro from Southwest to North China in the last active cycle of strong seismicity.(2)There is a corresponding relation between the peak of abnormal deformation at stations and the active period of strong earthquakes.(3)Since 1987, both the deformation anomalies and activities of strong earthquake not migrate obviously from Southwest to North China yet, but the migrate feature is also existent in North-South seismic belt of China.(4)In the next period, the probability of occurring earthquake with M_S≥6.0 in North China is low, but we are not sure about it for North-South seismic belt of China.

Key words:Deformation anomaly;Earthquake;Across-fault surveying