Analysis of recent deformation of Changbaishan Tianchi volcano
长白山天池火山近期形变场演化过程分析

The observation data of four leveling measurement campaigns between 2002 and 2005,six GPS surveys between 2000 and 2005 as well as the continuous tilt observation from 1999 to 2004 are systematically processed in this paper.The results demonstrate that:(1) From September 2000 to June 2002,the Tianchi volcano is basically in the quiescence status with no obvious deformation detected by GPS and InSAR observations;(2) In 2002 and 2003 there is abnormal surface deformation in the Tianchi volcano.The horizontal deformations derived from GPS observations display a typical radiation movement pattern with center at the crater lake,and leveling measurements also reveal rapid uplift around the lake;(3) The unrest process seems to have decayed rapidly year by year,for example,the maximum horizontal radiation movement of the GPS sites has decreased from a rate of 38.3mm/a between September 2002 and September 2003 to 15.8mm/a between September 2004 and September 2005,the maximum uplift rate of the leveling points also has decreased from 46.0mm/a between June 2002 and September 2003 to 5.0mm/a between September 2004 and September 2005.