Present-day Tectonic Movements And Earthquakes Relations In West Tianshan Of Xinjiang

West Tianshan Mountains is between Tarim and Jungar-Kazakhstan plate junction. The regional geological structure is complicated. There are important relations between present tectonic and earthquake in the west Tianshan Mountains region. By analyzing the relationship between west Tianshan mountains region earthquake catalog and present tectonic, making earthquake space-time distribution figure, the M- T figure, earthquake frequency figure. Using calculation and analysis results of observations data by GNSS in 2009 and 2013, making west Tianshan area velocity figure, velocity profile figure, the principal strain rate distribution figure, the surface expansion isoclines distribution figure, maximum shear strain rate contour figure. Through the above analysis, we get the following results:1.By analyzing the spatial distribution of earthquake in west Tianshan region, we believe that the uneven distribution of the earthquake, the epicenter of concentrated near the fault, along the fault strike. The quake’s epicenter connecting crosscutting fault in some areas, we speculated that there are some new structure to cut off the Tianshan old structural trend. West Tianshan region has a characteristics that earthquake in the southern area is more than in the north area.2.It points that seismic active period can be divided into four stages,1765-1855, 1860-1920, 1920-1985, 1985-2015 in the west Tianshan Mountains though M-T figure.3. It points that earthquakes in South and north Tianshan earthquake belt have relevance though M-T figure and the frequency distribution diagram4. It points that the south plate movement rate of fault is faster than the north, the west movement rate of E84o is faster than the eastern in the west Tianshan Mountains area though velocity profile figure. The difference of rates in the two sides of fault may be lead to earthquakes.5.It points that the main strain appear alternately 1~2 years later earthquake occurred on the strike-slip faults, Earthquake often occur in the region of surface expansion value 0 though west Tianshan area velocity figure, velocity profile figure, the principal strain rate distribution figure, the surface expansion isoclines distribution figure6. It points that the gravity field changes of west Tianshan are very frequent, gravity field change“enhance-weakened-enhance” correspond seismic trend activity “active-quiet-active”. the epicenters located in the high gradient zone of gravity variation and were close to the“0” equivalent line.