摘要
本文采用时空扫描方法,对1990年10月景泰Ms6.2地震前1979年1月至1990年9月震中周围5°×5°范围内的地震活动进行了分析,确定了该次地震的发震构造的闭锁区段。在发震构造带的东、西两段Ms≥2.0地震的活动具有相互呼应的特点,西吉—海原段的地震活动较门源—古浪段滞后3年。结合对b值异常区的空间变化图象的研究,本文还讨论了用对未来地震危险区进行长时段的时空扫描的方法确定构造的闭锁区段和闭锁起始时间的可能性。
The seismicity of 5°X5° around Jingtai region in Gansu from Jan. 1979 to Sep. 1990 is analysed by means of time space scanning. The blocking segment of seismotectonics of the Jingtai Ms6. 2 earthquake on Oct. 20, 1990 is determined. This blocking segment is located in the middle of Menyuan—Haiyuan tectonic belt. The scanning result shows that the earthquakes of Ms≥2.0 occurred mostly on Menyuan—Gulang segment and there are a few on Xiji—Haiyuan segment in that period. The seismicity of these segments echoes each other, and on Xiji—Haiyuan segment the seismicity is delayed for three years. It is possible, that the blocking segment and start time of blocking be found if analysing seismicity by means of time space scanning, and being combined with spatial variation pattern of b value of the seisrnie risk region for long period.
出处
《西北地震学报》
CSCD
1993年第2期24-29,共6页
Northwestern Seismological Journal
