河套盆地Ms≥5.5级地震前地震活动性特征

Charater of seismicity before the Ms≥5.5 earthquakes in Hetao basin

选取河套盆地及周边地区 (北纬 3 8.5°～ 42°,东经 1 0 6°～ 1 1 3°)为研究区 ,采用《中国地震目录》1 970～ 2 0 0 0 .8,ML≥ 2 .0级地震资料 ,应用“八五”、“九五”攻关研究成果 ,通过对河套盆地中强地震前地震活动图像和测震学指标的全时空扫描分析 ,提取具有预报效能的地震活动图像及参数 ,然后对河套盆地地震地质构造特征、历史中强地震时空分布特征和运用具有预报效能的地震图像、参数对河套盆地近期地震活动进行分析 。

The earthquake data(M L≥2.0)from 1970 to Aug.2000 in Hetao and its adjacent area(38.5°～40°N,106°～113°E)are processed with the method achieved in the scientific breakthrough project during'Eighth five years plan'and'Ninth five years plan'period.Through a thorough scan and analysis to the seismicity and seismometry index for the medium and strong earthquakes in the region,we pick up some seismicity images and parameters that have the function of prediction.Using these images and parameters we analyzed the geological tectonic feature,the earthquakes' distribution character and the recent seismicities in the area.We believe the seismic risk can not be ignored in hetao region.