大同－阳高地震的地磁异常研究

Analysis for the Geomagnetic Anomaly of the Datong-Yanggao Earthquake

对大同－阳高地震的地磁场△Ｆ时、空变化做了分析。认为６．１级地震前８个月山西北部地磁场△Ｆ出现异常，同年９月达高潮。６．１级地震后的１９９０年３月地磁场活动又出现了第２次高潮。２次高潮的异常幅度分别为１３．０ｎＴ和１３．２ｎＴ。大同－阳高地震的地磁异常具有时段长，连续性好，空间分布广的特点。

The space-time change of geomagnetic field △F before the Datong-Yanggao earthquake had been analyzed in this paper. It is suggested that the anomaly of the geomagnetic field △F in the north of Shanxi occurred for 8 months before the M6. 1 earthquake, the high value of the anomaly occurred in September of same year. In March of 1990 after the M6. 1 earthquake, second high value of the geomagnetic field occurred again. The amplitudes of the 2 high anomalous values were13. 0nT and 13. 2 nT respectively. The geomagnetic anomaly of the Datong-Yanggao earthquake characteriaed by long time, well continuity and wide space distribution.