1654年甘肃天水南8级地震补充考证

简要回顾了1654年天水南8级地震的研究历史，结合原有史料和新补充调查所获得的资料，核定了各破坏点的地震烈度，进而改绘了地震等震线图，其长轴方向为NE向。此次地震除造成大范围的城垣毁坏、房屋倒塌和人员伤亡之外，滑坡、山崩和堰塞湖等地震地质灾害也非常严重。其极震区位于礼县以东的西汉水河谷永兴镇—罗家堡—天水镇一带。该区发育了全新世活动的礼县—罗家堡断裂，其性质为左旋走滑兼正断。根据最新调查结果，该断裂沿礼县—盐关—罗家堡一带保存了地震陡坎、纹沟左旋和地震沟槽等地震地表破裂带形迹，其地理位置与历史资料考证所确定的极震区范围一致，印证了二者结论的可靠性和合理性。

Additional Textual Criticism of Southern TianshuiM8 Earthquake in Gansu Province in 1654

A large earthquake occurred at Luojiabu town, between the two cities of Tianshui and Lixian in the south of Gansu Province on July 21, 1654, that is, June 8-the eleventh year of Shunzhi in the Qing Dynasty. It is called the Southern Tianshui earthquake with magnitude about 8. This paper simply reviews the research history of the Southern Tianshui M8 earthquake in 1654. Then, according to the original historical earthquake data and new data by additional investigation in recent years, we check the intensities of the destoried sites, and then modify the seismic isoseismal line again, where the long axis is about the NE direction. This earthquake caused a large area of the town wall to collapse, civilian houses were ruined, and a large number of people died or were injured. It also caused serious seismic-geological disasters, such as landslips, rock collapses, and sag lakes. The epicenter area was located in the area from Yongxing, Luojiabu to Tianshui town along the valley of the western Hanshui River, west of Lixian county city. This area developed an active fault in Holocene, the Lixian-Luojiabu fault, which is characterized by left-lateral strike-slip faulting by normal components. According to recent field investigations, there are some earthquake rupture traces, such as seismic fault scarps, small valley left-lateral offsets, and seismic fault grooves along the Lixian-Yanguan-Luojiabu segment of the fault. The location of the earthquake rupture is consistent with the heavily-damaged area affirmed by historical textual criticism data, and confirmed both of them the reliability and rationality of the results.