1785年玉门惠回堡地震的震灾特点与发震构造

Disaster characteristics of Huihuipu earthquake in 1785 in Yumen,Gansu Province,and Discussion on Its Seismogenic Structure

摘要:

对1785年玉门惠回堡地震的历史资料考证和现场考察表明:本次地震的重破坏区位于玉门惠回堡至赤金堡之间,集中在火烧沟一带,其震级可达63/4级,震中烈度Ⅸ度左右。在构造上震区位于河西走廊西端的酒西盆地内,其内发育了新民堡、阴洼山和玉门等多条全新世活动断层,性质以逆断为主。其中新民堡断层和阴洼山的位置和走向与1785年地震的等震线长轴方向最为接近,至今仍保存有部分地震形变带遗迹。综合分析认为1785年惠回堡地震应与该区的新民堡断层和阴洼山断层的最新活动有关。

Abstract:

According to the detail textual research of the historical earthquake record and field investigation on Huihuipu earthquake in 1785 in Yumen city,Gansu province.It is found that the serious disaster area situated in Huoshaogou,between Huihuipu and Chijinpu.The magnitude of this earthquake is M63/4,and its epicenter intensity is about IX.Tectonically,the area lies in Jiuxi baisin,which is in western segment of Hexi Corridor.There are several Holocene faults developed in this area,such as Xinminpu fault、Yinwashan fault and Yumen fault,and so on.Most of them are reverse faults.Among them,the position and strike of Xinminpu fault are most consistent with the orientation of isoseismal long-axis of Huiningpu earthquake.And parts of deformation vestiges are still protected up to present.As analysing above,we consider that Xinminpu fault and Yinwashan fault is the seismogenic structure of Huihuipu earthquake in 1785.