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2014年2月12日在新疆于田县境内西昆仑山东段地区发生了Ms7.3级强烈地震,震后野外考察表明,这次地震在海拔4600~5100m的地区形成了由一系列张裂隙、张剪裂隙、剪切裂隙以及挤压鼓包和裂陷等雁行状组合而成的地表破裂带,破裂带沿阿尔金断裂带西南段的两条近平行的分支断裂阿什库勒-硝尔库勒断裂和南硝尔库勒断裂分布,整体呈NEE走向,全长约28km,其中,沿阿什库勒-硝尔库勒断裂展布的地表破裂带长约10km,主要呈N63°~65°E走向,以左旋走滑伴随伸展性质的破裂为主,最大左旋位移约0.7m,最大垂直位移约0.4m;沿南硝尔库勒断裂展布的地表破裂带长约15km,呈N54°~60°E走向,以左旋走滑伴随逆冲性质的破裂为主,最大左旋位移约1m,最大垂直位移约0.75m;上述两破裂带之间沿N15°E方向由零星的张裂隙和右阶雁行状分布的张裂隙或张剪裂隙组成的不连续破裂带长约5km,显示为伸展具有左旋走滑的性质;另外,在南硝尔库勒断裂北侧沿N100°~110°E方向展布一系列具有挤压、右旋走滑性质的地表破裂带长约4km,宽约2km,与NEE走向的左旋走滑破裂带构成同震共轭破裂带。这种特殊的地表破裂样式是近期发生的强地震中结构最复杂的走滑断层型地表破裂。发震断裂属于阿尔金断裂带西南段尾端分支断裂,它与郭扎错断裂和龙木错断裂构成“阿尔金断裂”向SW方向的延伸部分,它们是青藏高原西部晚新生代强烈活动断裂,其大地震活动是由于印度和欧亚板块间碰撞而产生大陆变形的应变能释放过程。
On February 12, 2014, a strong Ms7.3 earthquake occurred in the eastern section of the western Kunlun Mountains in Yutian County, Xinjiang. The field investigation after the earthquake showed that the earthquake formed a series of fractures in the areas of 4600 ~ 5100m above sea level, Zhang Shek fissure, shear fissure and the extrusion of kerogen packs and rifts geosyncline combination of surface rupture zone, rupture zone along the southwestern section of the Altyn Tagh fault in the vicinity of the two near parallel branch fault Ashkleid - Le fault and the South Coulter Fault, the whole length is about 28km. The surface rupture zone along the Ashcroft-Coulter Fault is about 10km in length, which is mainly N63 ~ 65 ° E to L-strike-slip along with extensional rupture. The maximum L-phase displacement is about 0.7m and the maximum vertical displacement is about 0.4m. The surface rupture zone along Nankun-Cole fault ruptures about 15km with an angle of N54 ° ~ 60 ° E strike, and the left-lateral strike slip is mainly accompanied by the rupture of the thrust nature. The maximum left-hand displacement is about 1 m and the maximum vertical displacement is about 0.75 m. Between the two ruptures along the N15 ° E direction, The discontinuous rupture zone consisting of Zhang cracks or Zhang shearing fractures distributed in order geese is about 5 km in length, In addition, a series of surface rupture zones with crushing and dextral strike-slip properties are distributed in the direction of N100 ° ~1110 ° E on the north side of the South Curur-Curia fault with a length of about 4km 2km, forming a coseismic conjugate rupture zone with the left-lateral strike-slip rupture of NEE. This special surface rupture pattern is the most complex strike-slip fault surface rupture in a recent strong earthquake. The seismogenic fault belongs to the tail branch fracture in the southwestern segment of the Altyn Tagh fault belt. It constitutes an extension to the SW direction of the “Altyn Tagh fault” with the fault of the Guozha fault and the Longmu fault. These seismogenic faults are strongly intense in the Late Cenozoic of the western Qinghai-Tibet Plateau Active faults, the major earthquake activity is due to the collision between India and Eurasia plate resulting in continental deformation strain energy release process.