摘要
1989年10月18—19日在大同—阳高一带发生M、=6.2地震及5个5级以上地震,形成震群型地震。我队以火车为运载工具的华北重力测网北环穿越震中区附近,原复测周期为一年。震后(1989年11月)对北环进行了检测,发现在原有重力变化的基础上,不仅未呈现恢复现象,而且重力变化继续加。1990年3月年度复测,重力变化保持在1989年11月震后水平,1990年9月再次检测,重力变化又朝同一方向继续发展。从重力变化趋势分析:此次大同—阳高地震与1988年7月23日阳原M_s=5.0地震是该区1983年后形成的趋势性异常背景上同一系列地震,目前该异常正继续发展,且有加速趋势,故对该区应进一步加强监视。
On October 18-19, 1989, a MS6.2 earthquake and five M > 5 earthquakes occurred in Datong-Yanggao district. The northern ring of our gravity network in North China transported by the train conducts the survey crossed the vicinity of the epicenter. The original repeat survey period is one year. This ring was checked after the Datong-Yanggao earthquake and found that based on the original variation - 74 ± 10-6cm/s2 in February 1989 and August 1986, the segment from Datong to Taiyuan not only showed no 'recovery' but also increased to -120 ± 10-6 cm/s2 after the event. A yearly repeated survey was made in March 1990, and its varied value was maintained at same level, -119 ± 10-6 cm/s2. It was checked again in September 1990, the change of this segment reached -155 ± 10-6cm/s2. The difference of the adjacent Datong-Taizhen-Zhangjiakou survey segments kept increase of positive value in the same direction. The contrast between the survey values in September 1990 and August 1986 is + 58 and + 47 ± 10-6cm/s2, respectively, namely, the total varied value from Datong to Zhangjiakou reached + 105 ± 10-6 cm/s2. Combining the past data, it can be considered that the Datong-Yangao earthquake and the Yangyuan MS = 5.6 earthquake on 23 July, 1988 belong to the same series of earthquakes on the tendency anomaly background formed in this area since 1983. At present, this anomaly is continuously developing and there is accelerating trend, so it should be intensely monitored.
出处
《地震》
CSCD
北大核心
1992年第3期44-52,共9页
Earthquake
