Analysis Of Modern Crustal Movement And Tectonic Activities In Qiongzhou Strait

the land deformation and tectonic activity monitoring are carried out by means of GPS deformation monitoring technique,taking the Qiongzhou Strait channel as an example,and the trend of crustal movement and fault activity are deduced.According to the existing information and design,respectively,25 GPS observation points are divided into five groups located in the Qiongzhou Strait,Maichen Town,Longtang Town,Hainan Dongzhai Port,Hainan Lingao County and stone town.Respectively,on the local and cross-strait for a total of four observations from 2014 to 2016,the data processing selected observation network as a base station,the full use of GPS differential positioning method,the use of pinnacle data processing software processing,and then calculate the previous observation of the displacement,The analysis shows that there is a counter-clockwise displacement field in the Qiongzhou Strait Area,and the annual southwest displacement of Dengloujiao rate is 84.3mm/a.The annual southeast displacement rate of Geyuan is 27.6mm/a,the annual southwest displacement rate of Xiyang is 18.0mm/a,the displacement of the north bank is irregular,The annual southeast displacement rate of Linyin is 26mm/a,The annual northwest displacement rate of stone town is 4.4mm/a.And there are a number of faults in the area,such as the Puqian-Qinglan fault,Puqian-Maniao fault,Lingao fault.The results prove that the faults are normal,reverse,left-lateral or right-lateral.The displacement rate of the west side of the fault is about 45.8mm/a,the direction is about 21°,the east direction is the north-east direction(1.4°-6.5°),the average rate is 46.4mm/a.The fault rate is 4.9-6.4mm/a,and the individual points are 25.2mm/a.(158°-215°);the west side of the fault displacement rate is 40.5mm/a,the direction is 27.5°.Fault a is located between Maigu and the other four points,and the activity fault b exists between Beizhu?Taodun and Dengloujiao?Duilouwai.The active fault c may exist between Lianzhi?Xiyang?Laolujiao and Xiatang?Geyuan in the Longtang observation network.But the Maichen-Beihe fault and the Longtang-Qujie fault are now inactive hidden fault.