【摘要】 史载公元849年10月20日,内蒙古河套地区发生大地震.对这次地震的震中位置、震级、烈度的认识目前存在较大分歧.作者在大青山山前断裂带活断层填图和古地震研究过程中,在大青山山前断裂中、西段,发现多处距今1000多年的地震形变遗迹;结合公元849年地震史料的进一步考证,表明大青山山前断裂带为公元849年地震的发震构造.宏观震中位置应在活动断裂变位量最大的包头铝厂至永富一带,地理坐标约为北纬40.4°,东经110.2°.震中烈度为Ⅹ度,震级为7.7.更多还原

【Abstract】 According to historical records,a large earthquake occurred in Hetao area of China’s Inner Mongolia Autonomous Region. Its epicenter,magnitude and intensity still remain disputable. We have discovered lots of earthquake rupture traces appeared more than 1000 years before along the middle and western segments of the Daqingshan piedmont fault while we mapped the Daqing-shan active fault and studied its paleoearthquakes. Result of textual research on the seismic data suggests that the Daqingshan piedmont fault is the causative fault of the A.D. 849 earthquake. Its macroscopic epicenter (40.4°N,110.2°E) is near the Baotou Aluminium Smelter (now Baotou Aluminium (Group) Co.,Ltd) and the Yongfu village,where vertical displacement of the fault is the largest. The estimated intensity and magnitude of this earthquake are Ⅹand 7.7,respectively.更多还原