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地震 ›› 1999, Vol. 19 ›› Issue (2): 183-189.

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唐山大震前后一般震群与前兆震群时空演化特征研究

薛艳, 梅世蓉   

  1. 中国北京 100036 中国地震局分析预报中心
  • 收稿日期:1998-04-27 修回日期:1998-09-23 出版日期:1999-04-30 发布日期:2022-09-19
  • 作者简介:薛艳,女, 1969年 12月出生,助理工程师,主要从事地震活动性研究工作。

THE SPATIO-TEMPORAL EVOLUTION CHARACTERISTICS OF GENERAL EARTHQUAKE SWARMS AND PRECURSORY SWARMS BEFORE AND AFTER THE TANGSHAN EARTHQUAKE

Xue Yan, Mei Shirong   

  1. Center for Analysis and Prediction, CSB, Beijing 100036, China
  • Received:1998-04-27 Revised:1998-09-23 Online:1999-04-30 Published:2022-09-19

摘要: 通过对华北地区 1970~1991年震群活动资料的研究发现: ①在唐山大震前 6~ 7年,华北地区震群活动出现波浪式起伏增强特点,大震后区域震群活动总体减弱; ②唐山大震前的震群逐渐形成条带分布,震后 3年条带走向消失 ;③唐山大震前的震群活动显示出一定的迁移性;④ 大震前 5年,满足 b、 K、 h、U 和 d中的任意 3个指标的前兆震群在 7. 8级主震周围大量出现。

关键词: 震群, 前兆震群, 唐山地震, 时空演化特征

Abstract: Through studying the data of earthquake swarms from 1970 to 1991 in North China, we find: ① Six or seven years before Tangshan earthquake, the enhancement of the earth-quake swarm activity showed a fluctuation feature. After the Tangshan earthquake, the regional swarm activity decreased generally; ② Before the Tangshan earthquake with M =7. 8, the distribution of the swarms showed in the form of zones, but after the earthquake, the zones disappeared; ③ Before the main shock, earthquake swarms showed a phe-nomenon of migration; ④ A large number of precursory swarms satisfying the comprehen-sive indexes only occurred around the mainshock epicenter within 5 years before the earth-quake.

Key words: Earthquake swarm, Precursory swarm, Tangshan earthquake, Spatiotem poralevolution characteristics