文章摘要

文章信息/Info

Title:: Analysis of Activity of Longgang Volcano Based on Vertical Deformation

Author(s):: HU Ya-xuan; WANG Qing-liang; WANG Xiong; (Second Crust Monitoring and Application Center,CEA,Xi'an 710054,Shaanxi,China)

摘要:: 首先分析了龙岗火山区及其附近20多年来5条水准路线所反映的垂直形变背景场情况,发现相对于长春基准点,长白山区东部和北部地区主要表现为大面积下沉运动,而龙岗火山区则表现为相对上升运动; 然后分析了龙岗火山区主要隆起区垂直形变场变化以及剪切和张裂变形率变化,所得结果均反映了长抚线发生了较明显的活动; 最后运用改进的Mogi模型,采用L曲线法反演了主要隆起区可能的压力源参数。结果表明,龙岗火山区岩浆的位置在42.1°N,126.5°E附近,与深地震测深研究结果近似。相对于长白山天池火山,压力源等效半径变化较大,达到183 m左右,源的深度在30 km左右,相对较深。

Abstract:: Firstly we analyze the vertical deformation rates of five leveling lines in more than twenty years in Longgang volcano region.The reates at the stations are calculeted relative to the Changchun fiducial position.The large area in the east and the north of the Changbaishan mountain is subsiding but the sites in the Longgang is rising.Then we analyze the vertical rate and the vertical strain in the main swollen region.Both of them show that the rate of the Fusong-Jilin leveling line is the biggest.At last,the source parameters are inversed by using the improved Mogi model.The data is analyzed mainly in the swollen region.The inversion method is L-curve.The location of the source is 42.1°N,126.5°E,that is the same as the result from the deep seimic sounding investigation.The equivalent radius of the pressure source is about 183 m,bigger than Tianchi volcano in Changbaishan Mountain.The depth is about 30 km,which is deeper than Tianchi volcano too.