GEOLOGICAL HAZARD CHARACTERISTICS AND MACROSCOPIC EPICENTER OF NOVEMBER 25, 2016, ARKETAO,XINJIANG, MW6.6 EARTHQUAKE |
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| Authors: | YAO Yuan CHEN Jie LI Tao FU Bo WANG Hao-ran LI Yue-hua CHEN Jian-bo |
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| Institution: | 1.Earthquake Administration of the Xinjiang Uygur Autonomous Region, Urumqi 830011, China;2.State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China;3.School of Earth Science and Geological Engineering, Sun Yat-Sen University, Guangzhou 510275, China |
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| Abstract: | The MW6.6 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. |
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| Keywords: | the 2016 Arketao MW6 6 earthquake seismic geological disasters sand liquefaction Kongur extensional system Muji Fault |
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