Abstract: The M_W6.6 Arketao earthquake occurred on November 25, 2016 in Muji Basin of the Kongur extensional system in the eastern Pamir. The region is the Pamir tectonic knot, one of the two structural knots where the India plate collides with the Eurasian plate. This region is one of the most active areas in mainland China. The seismogenic structure of the earthquake is preliminarily determined as the Muji dextral-slip fault which locates in the north of Kongur extensional system. Based on field surveys of seismic geological hazard, and combined with the characteristics of high altitude area and the focal mechanism solution, this paper summarizes the associated distribution and development characteristics of sandy soil liquefaction, ground fissures, collapse, and landslide. There are 2 macroscopic epicenters of the earthquake, that is, Weirima village and Bulake village. There are a lot of geological hazards distributed in the macroscopic epicenters. Sand liquefaction is mainly distributed in the south of Kalaarte River, and area of sand liquefaction is 1 000m². The liquefaction material gushed along the mouth of springs and ground fissures, because of the frozen soil below the surface. More than 60% of soil liquefactions are formed in the mouth of springs. According to the trenching, these liquefactions occurred in 1.8 meters underground in the gray green silty clay and silty sand layers. The ground fissures are mainly caused by brittle failure, and the deformation of upper frozen soil layer is caused by the deformation of lower soil layer. The ground fissures at Weirima village are distributed in a chessboard-like pattern in the flood plain of Kalaarte River. In the Bulake village, the main movement features of the ground fissure are tension and sinistral slip, and the directions of ground fissures are 90°~135°. The collapse and landslide are one of the important geological disasters in the disaster area. The rolling stones falling in landslide blocked the roads and smashed the wire rods, and the biggest rolling stone is 4 meters in length. We only found a small landslide in the earthquake area, but there are a large number of unstable slopes and potential landslides in the surroundings. The ground fissures associated with sand liquefaction are an important cause of serious damage to the buildings.

Key words: the 2016 Arketao M_W6.6 earthquake, seismic geological disasters, sand liquefaction, Kongur extensional system, Muji Fault

摘要： 对2016年11月25日新疆阿克陶M_W6.6地震灾区进行了初步的地震地质灾害实地考察，结合震区高海拔、高寒山区的特点，震源机制解数据，总结了砂土液化、地裂缝、崩塌、滑坡等地震地质灾害的分布及发育特征。本次地震存在2个宏观震中，即维日麻村和布拉克村，2处均发育大量的同震地质灾害。砂土液化主要分布在在喀拉阿特河南岸，面积达1 000m²，由于冻土层下部融层发生液化，液化物质沿已有泉眼、地裂缝喷出，其中60%的砂土液化为泉眼复发形成，根据探槽揭露的地层确定砂土液化发生在地下1.8m的灰绿色粉砂质黏土、粉砂层。本次地震地裂缝以脆性破坏为主，下部融土层发生变形后引起上部冻土层变形产生地裂缝是主要原因，其中维日麻村地裂缝以挤压作用形成棋盘状分布在喀拉阿特河河漫滩上，而布拉克村地裂缝以拉张和左旋走滑性质为主，地裂缝的运动方向在90°～135°，呈环形展布，具有向东侧拉张的趋势。崩塌与滑坡在震区也是重要的地质灾害之一，崩塌掉落下的滚石堵塞道路、砸断电线杆，最大滚石长4m，震区仅发生1处小型滑坡，但在其周边形成了大量的不稳定边坡和潜在滑坡体。本次地震地裂缝与砂土液化有伴生迹象，是造成房屋破坏严重的1个重要原因。

关键词: 阿克陶地震, 地震地质灾害, 砂土液化, 公格尔拉张系, 木吉断层