Pb-PbCl_2固体不极化电极在地电场观测中的作用和效能

THE EFFECT AND EFFICIENCY OF Pb-Pbl_2 SOLID NON-POLARIZED ELECTRODE IN GEOELECTRIC FIELD OBSERVATION

从二个方面讨论了Pb－PbCl2固体不极化电极在地电场观测中的效能和地震预报中的作用。一方面，由地电场的基本规律衡量了兰州、天祝用Pb－PbCl2固体不极化电极所得到观测资料的性质，认为观测量中绝大部分为地电场物理量，其中对地电场的快速变化（大地电场）记录的真实可靠；对缓慢变化（自然电场）除地下真实的变化外，还可能叠加有微小的电极电位漂移。不过这种漂移远比铅电极小得多，约15天小于1．5mV／km。另一方面，在兰州、天祝使用Pb－PbCl2固体不极化电极观测的2～3年期间，发生了永登5．8级地震和天祝5．4级地震。永登5．8级地震前，兰州、天祝台观测到地电、地磁日变形态崎变和突变，表明震源处有电磁辐射扰动；天祝5．4级地震前，由于天祝台与震中同处一条话动断裂，与断层垂直的测线上出现了明显的自然电位增大异常。所有这些观测结果表明，Pb－PbCl2固体不极化电极的使用可以推动地电观测与应用研究进入一个新阶段。

The efficiency of Pb-Pb12 non-polarised electrode in geoelectric field observation andits application in earthquake prediction are discussed in this paper. First, the observationaldata recorded in Lanzhou and Tianzhu stations by using Pb-Pb12,, non-polarized electrodesare analysed according to the basic regularity of geoelectric field. The results show thatsuch observational data mostly consist of physical values of geoelectric field, in which thefast change part is credible; the slow change part may include some small drift beside thereal underground change. However, such drift, smaller than 1. 5 mV/km in 15 days, ismuch smaller than that of Ph electrodes. Second, Pb-Pb12, non-polarized electrodes havebeen used for observation in Lanzhou and Tianzhu stations for 2～3 years, during that period two earthquakes, Yongdeng earthquake with M 5. 8 and Tianzhu earthquake withM 5. 4, occurred consequently. Through analysis it is found that distortion and abruptchanges in the pattern of daily geoelectric and geomagnetic field variations before Yongdeng earthquake appeared, which suggested that there were electro-magnetic radiation disturbance around the seismic source; before Tianzhu M 5. 4 earthquake, there were obviousincreased anomaly of natural electric potential in the observation direction, which is vertical to the fault, the reason is that Tianzhu station is just located along the seismic fault.All the results show that Pb--Pb12 non-polarized electrode is beneficial to develop observation work and application study of geoelectric field up to a new stage.