晋北区中小地震活动与晋冀蒙交界区6级地震的关系

Relationship between the Medium-small Earthquake Activities in Northern Shanxi Province and M6.0 Earthquake Occurred in the Juncture Area of Shanxi,Hebei,Inner Mongolia

摘要:

分析了晋北区中小地震(3.0≤ML≤5.0)的活动特征.统计发现,在1989年山西大同-阳高6.1、1996年内蒙包头6.4和1998年河北张北6.2级中强地震前1～2年内晋北地区的中小地震活动年频次有明显的增强-衰减-发震这一特征;震前主震近场区的地震条带活动对主震位置有预示意义,而较远场的地震活动仅反映主震前应力水平的增强.并有震前活动向未来强震区靠近的特征.

Abstract:

The characteristic of medium- small earthquake activity （ 3.0≤ML ≤ 5. 0 ） from 1982 in northern Shanxi province is analysed. It is found that 1-2 years before 1989 Datong-Yanggao ML6. 1 earthquake, 1996 Baotou ML6. 4 earthquake and 1998 Zhangbei ML6. 2 earthquake, the yearly frequencies of medium-small earthquake active showed obviously the process of in creasing-decreasing-main earthquake occuring. The strip-like seismic activities in areas near the main-shock before the event have the mean of predicting main-shock position,meanwhile the seismicities in the areas far from main-shock can only present the increasing of stress field level. The active of medium-small earthquake often move to the area where a strong earthquake would occur.