武威地电台映震能力讨论

RESEARCH ON THE REFLECTING EARTHQUAKE ABILITY OF WUWEI GEOELECTRIC STATION

摘要:

本文研究了武威地电台周围150km范围内发生的景泰6.2、门源6.4、天祝西4.7、旦马5.6、雅布赖4.7级地震和共和7.0级地震(Δ=270km)该台地电阻率(ρ_s)变化,结果显示:对于前4次地震,该台EW进测值出现10^-1-10^-2量级的ρ_s短临异常,共和和雅布赖地震前后观测到1O^-1量级的ρ_s短期下降异常。作者研究认为,ρ_s异常可能是该台EW这探测范围内介质不完整,孕震后期震源力学过程引起地下水沿测区内次级断层、裂隙或裂缝活动造成的。最后本文指出,该台EW道测值对其周围特定位置发生的中强以上地震,在短临阶段映震能力较强。

Abstract:

Earth-resistivity (ρ_s) changes of Wuwei geoelectric station before and after earthquakes of M 6.2 in Jingtai county,M 6.4 in Menyuan,M4.7 in West of Tianzhu,M5.6 in Danmaand M4.7 in Yabulai (Δ ≤ 150 km),as well as M7.0 in Gonghe (Δ=270 km) in this paper.Conclusions are follows:(1) Short-impending ρ_s anomalies up to 10^-1-10^-2 magnitude were recorded in EW observation direction at the station before the former 4 earthquakes,short-term ρ_s anomalies up to 10^-2 magnitude which were decreased were recorded before the Gonghe and Yabula earthquakes.(2) The short-impending ρ_s anomalies in the direction were probably caused by the move of ground water along second faults,rifts or fissures in the late period of seismogenic process,since earth medium within the range of exploration in the direction was fragmentary.Finaly,author thinks,the reflecting earthquake ability of short-impending ρ_s change in EW direction of the station is higher for moderate and strong earthquakes occurred in certain region around the station.