晋冀蒙交界区5.0级以上地震演化过程之研究

A Study on Evolution of Earthquakes Larger Than M 5.0 in the Juncture Area of Shanxi, Hebei and Inner Mongolia.

研究了晋冀蒙交界地区5.0级以上地震的时空分布特征、孕育演化过程,结果表明,该区5.0级以上地震空间分布受区内主要活动断裂控制,研究区孕育1次6.0级以上地震需9a以上。5.0级以上地震的孕育演化过程具有共性:表现为孕震构造伴有中小地震(3.0<M≤5.0)间歇活动,主震前出现2个月～8个月时段的平静,末次中等地震与主震有较好的对应关系,震前2a中等地震明显由外围向主震震中迁移等。

Feature of space-time distribution of earthquakes larger than M 5.0 in the juncture area of Shanxi, Hebei and Inner Mongolia and their seismogenic process and evolution are studied. The results show that spatial distribution of earthquakes larger than M 5.0 is controlled by main active faults in this area and the time to form an earthquake larger than M 5.0 is longer than 9 years. Seismogenic processes and evolutions of earthquakes larger than M 5.0 in this area have some common behaviors: seismogenic processes are accompanied by interim medium and small seismicities; there is a quiet period, about 2 to 8 months, before a main shock; the last medium earthquake well correspond to the followed main shock; medium earthquakes begin to move towards to epicenter of a main shock apparently from outer places, before 2 years.