关键词: 中深源地震, 火山地震, 火山活动状态, 西北太平洋俯冲带, 长白山天池火山

Abstract: On the basis of geodynamics of Changbaishan Tianchi volcanism,we analyzed comprehensively the intermediate and deep focus earthquakes induced by the subduction of the northwest Pacific plate and the relation between the volcanism of Changbaishan and the change tendency of gas released in the thermal spring.We think that volcanic activity of Changbaishan caused by the disturbance of mantle convection with the subduction of Northwest Pacific plate to the northwest of 35癗 is divided into three stages from the beginning of 1999 to the present.The first stage with the beginning of the disturbance is from June,1999 to May,2002;The second stage with the intensifying of disturbance is from June,2000 to 2004;And third stage with the decaying of disturbance is from 2005 to now.By analyzing the above three stages,we discussed the present activity regime.We analyzed the rhythmic seismicity between the seismically active period and the quietude period of the area from the Japan Sea to the deep-focus earthquake zone of Northeast China and the possibility of eruption of Changbaishan Tianchi volcano in the future.

Key words: northwest Pacific subduction zone, intermediate and deep focus earthquake, Changbaishan Tianchi Volcano, volcanic earthquake, state of volcanic activity