2015年4月15日内蒙古阿拉善左旗发生MS 5.8地震,震中位于鄂尔多斯块体西北边缘,吉兰泰断陷盆地北端.古近纪以来,受喜山运动强烈影响,阿拉善地块急剧抬升,断裂活动加剧,近年来小震活动呈密集分布.研究地震序列分布,序列整体分布较集中,主体呈北东东向展布,为主余型地震.由震源机制及烈度考察,发现极震区长轴均为北东东向,与北东方向的磴口—本井隐伏活动断裂走向基本一致,综合判定该断裂可能是此次地震的发震构造.%Alashan Left Banner MS 5.8 earthquake occurred in the Inner Mongolia Autonomous Region on April 15, 2015. The epicenter was located in the northwest edge of Ordos block, the northern tip of Jilantai fault basin. Since Paleocene, the region is strongly affected by the Himalayan motion and the Alashan block sharply upraising. The fault activities intensified and the region seismic activity is very frequent in recent years. The overall distribution of earthquake sequence distribution is quite concentrated. The distribution of the main part is in NEE and the sequence type is main shock-aftershock type. The long axis of focal mechanism and intensity investigation of meizoseismal area is in NEE, which is similar with Dengkou—Benjing hidden active faults. Through the comprehensive judgment, it shows that the fault may be the seismogenic structure of the MS 5.8 earthquake.
展开▼
