Changbaishan Volcano Deformation Monitoring Application Base On Gps Survey

Changbai Mountain Tianchi Volcano, located at the border between China and North Korea, is over 310km away from Changchun, the provincial capital of Jilin Province, in straight-line distance. Its range of geographic coordinates is NL 41°20'-42°40', E 127°00'—129°00'. The whole region is over 20 million square kilometers, which is one of the largest natural reserves in China. Baiyun Peak, its highest peak in China and the highest peak in Northeast China, has 2,691m altitude, and General Peak, its highest peak in North Korea, has 2,749m altitude. Changbai Mountain Tianchi has 2189.7m altitude water surface, as deepest as 373m, over 10 square kilometers of water area, and over 2 billion tons of fresh water. Tianchi volcano's terrain centers on the crater and declines around, so it can be divided into 3 landform units, namely, Tianchi Volcano cone, mountain-foot tilted volcanic plateau and lava plateau; 16 summits surround Tianchi; from the conic mountainside, the terrain inclines stepwise and downwards, the gradual slope extends to the cone which transits to the mountain-foot tilted plateau by the grading angle. Changbai Mountain volcanic region has a temperate continental mountain climate with short summer, long winter, coldness, large temperature difference between day and night, and irregular variations of weather. The spring there is windy, and the autumn is misty; the lowest temperature in winter in a year can reach-40℃; and it is summer and autumn that are favorable for observation by flowing GPS and leveling.Changbai Mountain Tianchi volcano is a large composite volcano which is still active since Holocene; since 5,000 years ago, Changbai Mountain Tianchi volcano has erupted for several times, among which, its eruption over 1,200 years ago was scarcely disastrous in the world; the volcano research in "Ninth Five-Year Plan" shows, Changbai Mountain Tianchi still has signs of magmatic actions, and the danger of its eruption again cannot be neglected. To effectively monitor and research the crustal movement of Changbai Mountain Tianchi volcano, since 1999, the cave fixed deformation station for continuous observation, GPS network for regular observation, and the precision leveling measurement lines have been established in the region, so as to form the relatively complete deformation monitoring system for Changbai Mountain Tianchi volcano by combining with points, lines and surfaces; and several times of GPS and leveling measurements for the region have been carried out for the latest crustal deformation materials of Changbai Mountain Tianchi volcano. The paper arranges and analyzes the said deformation materials, brings forward the latest features of the crustal movement of Changbai Mountain Tianchi volcanic region, combines other monitoring materials for the integral research, and analyzes all possible reasons.This thesis is a study on the deformation monitoring of the Changbaishan Volcano by using the techniques of Global Position System(GPS), Deformation observation is the main maeasure to monitor the activity of magma and forecast volcano eruptions.Although some tectonic activity and deformation can not be at the peak before volcano eruption,the majority of the volcanic eruptions did has obvious surface deformation.Accurate measurements of surface deformation can be used for the study of volcanic activity and volcanic eruption prediction.We set up 8 sites 14 baselines of GPS station web and installed it on the volcano area to seeks to characterise the ground deformation within the volcanic edifice. This thesis discussed that site selecton and data proceeding about GPS monitoring station using TEQC,GAMIT/GLOBK software in the years of 2005-2008.Ⅰconclude that the Changbaishan Volcano area have obvious deformation, and this is a new evidence about volcano activity.The result shows, from 2005 to 2008, there has been obvious deformation on the ground of Changbai Mountain Tianchi volcanic region. In the vertical direction, the accumulated variation of the leveling lines'height difference has reached 6.8cm, and the region closer to the crater has bigger deformation. In the horizontal direction, centering the crater, the observing points reveal the total displacement variations in radical shape, and the maximum displacement is 38cm; the massif has obvious expansion, when the maximum surface expansion reaches 6×10-6/a. The above variations have gradually become regular variations after 2006. During that period, there have been frequent volcanic seismic activities in Changbai Mountain Tianchi volcanic region, and other monitoring materials also show the synchronously abnormal variations. The paper analyzes and discusses the possible reasons of the above mentioned variations, and considers they are caused by the latest time of magmatic action of Tianchi Volcano.