中强地震前菏泽、郯城地震地电阻率各向异性值变化特征

Variation Characteristics of Geoelectrical Resistivity Anisotropy Values before Moderate-strong Earthquakes in Heze and Tancheng Stations

摘要:

对山东菏泽和郯城两台站地震地电阻率观测资料进行处理的基础上,研究了地震地电阻率各向异性的前兆异常特征,得出两台站周围300 km内的5级以上地震发生前均存在明显的地震地电阻率各向异性前兆异常,在中强地震发生时其各向异性值基本处于高值附近。对其物理机理进行了初步的探讨。

Abstract:

Based on the processed observation data of geoelectrical resistivity from Heze and Tancheng stations in Shandong province, the characteristics of precursor anomaly of geoelectrical resistivity anisotropy values are researched. The result indicates that there are obvious precursor anomalies of the anisotropy in both stations before M ≥5 earthquakes occurring in range of 300 km, and the anisotropy values change in a stable variation range near the high value. Meanwhile the physical mechanism of this phenomena is discussed.