摘要
根据历史地震资料的考证结果,734年天水地震的极震区位于秦州中都督府、麦积都尉一带,今天水市秦城区、北道区和麦积山一带,震中烈度达Ⅹ度,震级71/2级左右。其等震线长轴方向为NW向,大致与西秦岭北缘断裂带的甘谷-武山断裂段相吻合,极震区正好位于甘谷-武山断裂段的东端。综合分析认为,734年天水71/2级地震的发震构造为西秦岭北缘断裂带的甘谷-武山断裂段东端。
Tianshui area locates at the northeastern margin of Qinghai-Tibetan plateau and the middle segment of the north margin of western Qinling tectonic zone. In history, several strong destructive earthquakes happened in the area. Because of the very long history and that the historical records are not quite clear, it is very difficult to study them in nowadays, and most of them became historical knotty problems. The Tianshui earthquake in 734 AD is one of the large earthquakes
On March 23, 734 AD, a large earthquake happened in Qinzhou of Tang Dynasty, now the vicinity of Tianshui City, causing serious seismic disasters as ＂ the earth ruptured and closed again, nearly all the houses damaged, about 4000 people dead, hills changed into valleys, and towns covered by landslip, and so on＂.
According to the detail textual research of the historical earthquake records, the meizoseismal area of the 734 AD Tianshui earthquake is in the Qinzhou and Maiji area, now, the Qincheng, Beidao and Maijishan area of Tianshui City. The epicenter intensity is about X, the magnitude is about M 7^1/2. The direction of long axis of isoseismal line is NW, consistent with the strike of the eastern segment of Wushan-Gangu Fault of the northern margin of western Qinling active fault zone. The meizoseismal area is just in the step-over zone between the left-lateral strike-slip faults, i.e. the Tianshui-Baoji Fault and the Gangu-Wushan Fault, an area prone to strong earthquake.
Comprehensive analysis indicates that the quake is the east segment of the Gangu-Wushan Fault of the northern margin of western Qinling active fault zone.
出处
《地震地质》
EI
CSCD
北大核心
2007年第1期51-62,共12页
Seismology and Geology
基金
国家自然科学基金(40372086)
中国地震局"南北地震带中强地震短临跟踪"
甘肃省科技攻关基金项目(2GS054A44015)资助
关键词
734年天水地震
历史地震考证
发震构造
西秦岭北缘断裂
Tianshui earthquake in 734 AD, Historical earthquake textual research, Causative structure, Northern margin of western Qinling fault
