关于偶极法预报地震的试验研究

1982年6月到12月初在宁夏海原地区进行了偶极法连续观测试验。试验共布置了2条测线5个观测点,供电电流保持在70—100安培左右,观测精度约0.5%。人工电位差脉冲观测使用改装的小型仪器车每天流动定时测量一次,每次观测20组脉冲,观测精度在3%左右。观测结果表明:在8月14日海原北2.7级地震前(测区距震中17公里)各观测点地电阻率都明显出现异常,异常幅度8—20%不等。四极对称装置浅层探测异常幅度约1.5%。11月5日距震中区约110公里同心北3.3级地震前,赤道式装置的2个观测点有明显异常,异常幅度约7—9%。本文所观测到的前兆异常可用郭增建同志提出的地震前兆优显层的理论得到解释。

THE TEST RESEARCH OF APPLING DIPLOE METHOD IN EARTHQUAKE PREDICTION

The continual testing observation was carried out in Haiyuan, Ninxia from June to December 1982. Five observationary points along two observation lines were arranged. The current was about 70-100A, and the accuracy of observation for the current about 0.5%. We observed the man-made potential difference using a small instrument car once a day and twenty pulses of the potential were observed every time, and the accuracy of observation of the potential was about 3%.The results have shown that in the resistivities observed at all the observational points occurred abnormalities of total change of 8-20% before the earthquake Ms=2.7 in Haiyuan on August 14,1982(epicentral distance was about 17km), meanwhile the abnormal change observed by the four-pole symmetric observation which is used to survey the resistivity of shallow layer was only about 1.5%.There were other anomalies recorded at the observational site with the total change of 7-9% in geoelectric resistivity before another earthquake(Ms=3.3, Nov. 5,1982)in the north of Tongxin, Ninxia, which was 11okm from the observational site. It seems to the author that the anomalies could be explained on the basis of the hypothesis that there would exist a layer in the crust, where the precurssor is stronger than inother region of the crust in the preparing process of earthquakes and which is called the precursor advantageous layer proposed by Mr. Guo Zengjian.