Study On Vertical Deformation Monitoring Of Regional Crust In Yunnan Province

Kunming basin and its surrounding locate on the boundary between the Yangtze paraplatform and Sichuan-Yunnan anticline and Yunnan dongtai fold belt this two second-order tectonic units. Kunming basin in new tectonic zone belongs to Kunming sag level 3 new tectonic zone, and at the same time is a part of Sichuan and Yunnan fault block uplift zone. The uplift background of Kunming basin in region tectonic zone belongs to strong fault Hupen district of eastern Yunnan.GPS’application in the research of regional crustal movement can accurately and timely get the plate motion information. Thus it makes access to information of modern crustal movement and vertical velocity of an area in a short time, and test the existing geological model. Based on widely summarizes and experience of predecessors’research achievements and, combining the geological structure background and seismic characteristics of Kunming basin, using the data in Kunming CORS site,this paper studied crustal horizontal movement and vertical deformation Kunming the surrounding in depth. The results showed that:(1)During October to November of 2014, stand contour of horizontal speed variation is intensive in southeastern Xiaohe station,northern Jinning station and northwestern Shilin station. Stand contour is thin between northwestern Xiaohe station and Luquan station. Thechange rate of Xiaohe station, Jinning station and Shilin station is big while the rate of Luquan station is slight. This shows that east area of Kunming basin has large range crustal movement while western has small range crustal movement(2)During November to December of 2014, according to variation from 4 stations, we can find that the horizontal velocity of stand contour of eastern Jinning station, western Shilin station is very dense, with big gradient velocity; Stand contour is relatively thinner in southwestern Xiaohe station, northwestern Luquan station with small big gradient velocity. This suggests that crust in northwestern Kunming basin is relatively stable, and is intense in eastern and southern. Stand contour varies abnormally near Xiaojiang fractures, which belongs to crustal stress concentration area.(3) During October to November of 2014, vertical deformation contour variation of north-south direction is regular, with north higher and south lower. Shilin has a large range of vertical change in northwest while Luquan station has the smallest variation. East-west vertical deformation contour map shows regional rise with biggest abnormal vertical change in northwestern Shilin, northeastern Jinling and southeast Xiaohe station. The whole Kuming in contour is high eastern and lower in western. According to variation discipline of vertical deformation contour, southeastern raises fast and northeastern raises slower.(4)Spatial distribution of vertical deformation is flatin longer time interval. Vertical deformation overall change trend is higher in eastern and lower in western, and higher in northern and lower in southern. With increasing gradually in observation time, regional vertical deformation rate gradually reduces.