【摘要】 通过对西北地区8次MS≥7强震前的MS≥5地震活动特征和3次MS≥7强震前的ML4地震演化的研究,发现西北地区7级强震前存在较大范围的MS≥5地震平静或MS5地震空区。该地区强震前存在ML≥4地震空区的演化,一般表现为孕震区周围出现平静—活跃、持续平静和平静区逐步向未来震中收缩的特征。更多还原

【Abstract】 Analysis on the seismic activity characteristics of MS≥5 earthquakes before eight MS7 strong earthquakes and seismic activity evolution of ML4 earthquakes before three MS7 strong earthquakes in the Northwest region,we found that there exited a large range of seismic quiet area of MS5 earthquakes and seismic gap of MS5 earthquakes.The evolution of seismic gap of ML4 earthquakes exited before MS7 strong earthquake in Northwest region,and its characteristic appeared the quiet-active、sustained quiet and the quiet area gradually coming to the epicenter in the future in generally.更多还原