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对汶川MS8.0地震震中周围17个台站的地电阻率观测资料进行了处理.以2007年的地电阻率观测数据为背景值,计算出每一个台站NS和EW两个测向2008年的地电阻率月均值相对变化的绝对值,然后选择较大的值作为当月的相对变化值.最终获得了汶川地震前5个月的地电阻率异常变化图像.结果表明,随着发震时间的临近,地电阻率异常分布的范围逐渐缩小,并最终集中分布在汶川地震震中附近;在临近发震时间(2008年3,4月),地电阻率异常分布的长轴方向与汶川MS8.0地震的破裂方向、龙门山断裂带走向或地震烈度分布的长轴方向几乎垂直,而与其震源机制解的主压应力轴方向基本一致.
Ground resistivity observations of 17 stations around the epicenter of the Wenchuan MS8.0 earthquake were processed.With the background data of the earth resistivity in 2007 as the background value, two stations of NS and EW are calculated for each station in 2008 And then select the larger value as the relative change value of the month.Finally, the image of the anomaly of the earth resistivity in the first 5 months of the Wenchuan earthquake was obtained.The results show that with the time of occurrence of the earthquake In the vicinity of the epicenter (March and April 2008), the long axis direction of the anomalous distribution of earth resistivity was in the same direction as Wenchuan MS8. 0 earthquake, the direction of the Longmen Shan fault zone or the distribution of seismic intensity is almost perpendicular to the long axis but not to the direction of the principal compressive stress axis of the focal mechanism solution.