甘肃地区地震活动特征

THE CHARACTERISTICS OF SEISMIC ACTIVITY IN GANSU REGION

摘要:

本文研完了甘肃及邻近地区最近一个平静期的地震活动特征。主要讨论了:1)小震、中强震是围绕在本世纪历史强震震中区分布在断裂带上或交汇地区及弧形构造的顶部,震源绝大多数分布在地壳中10-30公里的范围;2)1966-1979年甘肃地区小震、中强震的频度和活动强度曲线的峰值与滇川青地区M_s ≥ 6.5级强震有同步性。对比年、季、月的频度曲线可以提取外区强震发生前的前兆信息,並指出分区频度曲线对应外区强震在时空方面的不均匀性;3)由青藏高原构造运动所控制的滇川青与甘肃地区的地震迁移特点,表现为南强北弱和南北强震呼应两种类型。並且,总是甘肃地区处于平静阶段时,滇川青地区处于活动高潮阶段。

Abstract:

The characteristics of seismic activity in Gansu province and its nei-ghbourhood during the recent relatively quiet period have been studi-ed in this paper.The synchronism of the peak values in the curves of fre-quency and seismicity strength of the small and moderate earthquskes in Gansu region during the period of 1966-1979 with the occurrence of earthquakes of magnitude M_s≥6.5 in Yunnan,Sichuan and Qinghai pro-vinces has been mainly discussed.