中强地震前空区图象一例

1980年内蒙博克图5.6级地震前3.5年左右在主震震中附近形成小震密集区,在密集区外围形成环带空区,在主震发生前两年,环带空区消失,同时在震中附近形成孕震空区。随时间进程,孕震空区、密集区和环带空区间的内外频次比有下降—回升—峰值发震的特点,是一个典型的空区图象震例。

AN EXAMPLE OF SEISMIC GAP PATTERNS BEFORE MODERATE EARTHQUAKE

There existed a concentrated area of smaller shocks near the epicenter of major earth-quake and an annular seismic gap surrouding the above area the about three and a halfyear before Boketu earthquake with Ms=5.6, 1980. The annular gap disappeared andformed a seismogenic gap near by the one of major earthquake the two years before mainshock. It is a typical example of seismic gap patterns.