断层气体的释放与地震活动关系的初步研究

Primary Study of Fault Gas Release in Relation with Earthquake Activity

北京城北塔院断层土壤气中的He^4/Ne^(20),He^4/Ar^(40),Ar^(40)/Ar^(36),CH_4/CH_4^(16),CO_2/Ar和N_2/Ar比值与1990年7月21日大海坨4.5级地震和1990年9月22日沙河东4.0级地震有很好的对应关系,而且在1991年1月29日山西忻州5.1级地震,2月20日高丽营3.0级地震和3月26日大同5.8级地震前后,He^4/Ar^(40)和Ar^(40)/Ar^(36)的值均有异常变化。并且利用塔院断层土壤气中CO_2/Ar,N_2/Ar,CH_4/CH_4^(16),He^4/Ne^(20),He^4/Ar^(40)和Ar^(40)/Ar^(36)的值,在地震前10天和1天预报了9月22日沙河东4.0级地震。同样,根据He^4/Ar^(40)和Ar^(40)/Ar^(36)的异常变化,于3月9日向地震局值班室汇报了异常情况。研究表明,气体地球化学的这几项指标能确切地反映地壳深处应力变化的信息。

The variations of He4/Ar40, He4/Ne20, Ar40/Ar36, CH4/CH416, CO2/Ar and N2/Ar ratios in the soil gas of the Tayuah fault have a very good relation with the Dahaituo earthquake ( Ms = 4.5) in July, 1990. Based on the anomalous ratios of CO2/Ar, N2/Ar, CH4/CH416, He4/Ne20, He4/Ar40 and Ar40/Ar36 in the Tayuan fault' s soil gas, the eastern Shahe earthquake ( Ms =4.0) was predicted ten days and one day respectively before its occurrence. The studies show that the indicators of geochemical gas changes could reflect the information of stress in the deep crust.