2015年内蒙古阿拉善Ms5.8地震前地电阻率变化特征研究

摘要

The Ms5.8 earthquake occurred at Alashan Zuoqi of Inner Mongolia,China.Six earth resistivity variation stations located about 500 km from the epicenter of the earthquake were discussed and analyzed.The trend of earth resistivity decreases about one year prior to the Alashan earthquake at Shizuishan,Yinchuan,Haiyuan and Guyuan.Especially,earth resistivity of Shizuishan,the nearest station from the epicenter,shows the maximum amplitude of decline.Earth resistivity of Shizuishan,Yinchuan,Haiyuan,Guyuan show distorted anomalies in annual variation.The relative mean square deviation of earth resistivity shows sudden jump 1～3 months prior to this earthquake.%本文讨论了2015年内蒙古阿拉善M5.8地震前500 km范围内6个台的地电阻率变化,得到如下结论:①石嘴山、银川、海原、固原等台站震前1年半左右出现了较明显的趋势下降变化,尤其以距离震中最近的石嘴山台下降幅度最大.②利用年变畸变方法分析了石嘴山、银川、海原、固原台的电阻率震前几年的年度变化发现几个台震前均发生了年变化畸变现象.③几个台地电阻率原始小时值的均方差在震前1～3月内均同时出现了大幅度突跳现象.