玛多M_(S)7.4地震前地电阻率变化

Earth Resistivity Changes before Maduo M_(S)7.4 Earthquake

分别运用原始曲线分析法和归一化速率法分析2021-05-22玛多M_(S)7.4地震震中400 km范围内4个地电阻率台站的数据变化。结果表明:1)玛多地震前,4个地电阻率台站资料出现不同程度的异常变化,其中玛曲NW、金银滩EW、甘孜N10°E、拦隆口EW测道原始曲线变幅最明显,表现为小时值突跳变化、日均值加速变化和曲线转折变化、月均值破年变和保留年变形态的趋势变化;2)玛曲NW、金银滩EW、甘孜N10°E、拦隆口EW归一化速率曲线在玛多地震前均出现超阈值现象,但各自归一化速率形态不同;3)综合分析认为,4个台站地电阻率资料异常变化与玛多M_(S)7.4地震的孕育及活动有关。

The original curve analysis method and normalized variation rate method were applied to analyze the data changes of four earth resistivity stations within 400 km of the epicenter of Maduo M_(S)7.4 earthquake on May 22,2021.The following results were obtained:1)Before the Maduo earthquake,the data of four earth resistivity stations showed different degrees of anomalous changes,among which the original curve changes of the Maqu NW,Jinyintan EW,Ganzi N10°E,and Lanlongkou EW channels were the most obvious,which manifested hour value jumping changes,accelerated changes in the daily mean values and curve turning changes,as well as trend changes in the monthly mean values of the broken and preserved annual variation patterns;2)The normalized rate curves of Maqu NW,Jinyintan EW,Ganzi N10°E,and Lanlongkou EW all exceeded the threshold before the Maduo earthquake,but their respective normalized rate patterns are different;3)The comprehensive analysis concludes that the anomalous changes in the earth resistivity data of the four stations are related to the gestation and activity of the Maduo M_(S)7.4 earthquake.