10余年来甘肃省中强地震的发震构造特征

The Characteristics of Seismogenic Structure of Middle-strong Earthquakes in Recent 10 Years, Gansu Province

摘要:

归纳总结了1995年以来甘肃省所发生的9次MS5.0以上破坏性地震的发震构造特征,综合分析了其共性和个性特点。结果表明:所发生的中强破坏性地震大多位于活动性较弱的次级活动断裂带上或主干活动断裂带边缘,其分布具有时间上的分段性、空间上的分区性和迁移性特点,并具有从山前向盆地内部扩展的发展趋势。

Abstract:

The characteristics of seismogenic structure and tectonic backgrounds of 9 Ms≥ 5. 0 earthquakes occured in Gansu Province since 1995 are summarized, the generalities and distinctive features of the structures are analyzed. The results indicate that： most of the middle-strong earthquakes in recent 10 years in Gansu main occured on the secondary active fault zones, where activity is weak, or on the edge of main fault zones. The earthquake are results of regional stress field adjustment, and their characteristics are occuring by stages in time, distributing in divisional zones in space and migrating from the front of Mountain to the interior of thrust basins.