大地介质极化率和二次场衰减特性时序观测与研究

大地介质极化率和二次场衰减特性时序观测是探索介质新的电性参数作为前兆观测项目的研究课题。经两年的观测研究发现，极化率存在年变化形态；主要研究的放电时段应放在１０～１００ｍｓ范围；在观测时段（１９９４ ０３～１９９５ １１）内台站３００ｋｍ范围发生的唯一一次大于５．０级的苍山５．２级地震（△３０４ｋｍ）前，极化率参数异常不明显，而极化率衰减度在该次地震前出现异常，衰减曲线极大值位移、曲线畸变、半衰时亦出现高值。对比地电阻率与极化率衰减度和半衰时的观测数据，在苍山５．２级地震前异常时间同步，呈低电阻率、高衰减度、高半衰时变化。研究结果表明应用介质新电性参数极化率作为前兆观测项目是可行的。

TIME SEQUENCE OBSERVATION AND RESEARCH FOR POLARIZABILITY OF GEOMEDIUM AND CHARACTER OF SECOND FIELD ATTENUATION

Through observation for two years, the annual variation forms of geoelectric polarizability are discovered. The discharge interval of main research should be 10～100ms. Only one earthquake over M S 5.0 was the Cangshan that of M S 5.2 occurred in epicentre distance 304km in the observation interval of Mar. 1994～Nov. 1995. Before this earthquake the polarizability parameter anomaly was not obvious, and it is anomaly that high polarizbility attenuation degree occurred, the maximum value of attenuation curve displaced, the curve had deformation, half period had also high value, and they had synchronazatity, resistantity was low. It is indicated that polarizability of new geoelectric parameter as the precursor observation term is good.