中国大陆西部7级以上地震前地震空区演化过程分析

Analyze on Evolution Process of Seismic Gap before M≥7. 0 Earthquakes in the Western Part of China Mainland

通过对1970 ～2010年中国大陆西部M≥7地震前地震空区演化的研究,认为M≥7大震前中等以上地震空间展布呈现有规律演化过程,M≥6、M≥5、ML≥4地震在同一构造区域逐渐出现大面积平静,形成不同震级档配套的地震空区.这一图像演化过程对M≥7大地震的孕育区域有一定的指示意义,对M≥7地震的中期预测有积极作用.

By studying the evolution process of seismic gaps before M≥7.0 earthquakes occurred in the western part of China mainland from 1970 to 2010,it was suggested that the spatial distribution evolution process of moderate and strong earthquakes showed relatively regular before M≥7.0 earthquakes,which showed that M≥6,M≥5and ML ≥4 earthquakes gradually appeared very quiet in a large area at the same tectonic region,forming seismic gaps with different magnitude intervals.The evolution process of such patterns is the guidance of the pregnancy zone of M≥7.0 earthquakes,and has an important effect on the medium-term prediction on the M≥7.0earthquakes.