长白山天池火山地震活动机理研究

RESEARCH ON THE VOLCANIC EARTHQUAKE ACTIVITY MECHANISM IN CHANGBAISHAN TIANCHI AREA

对1999年以来长白山火山观测站记录到的火山地震活动进行了研究,发现在西北太平洋5.0级以上中深源地震发生前后,均有火山地震活动发生变化。我们统计发现有以下三种情况:第一种是深源地震发生后火山地震随之增强;第二种是火山震群活动结束后发生中深源地震;第三种是深源地震前后火山地震活动频繁,在火山地震活动较少时发生中深源地震。本文通过对近年来长白山火山地震活动与西北太平洋俯冲板块的中、深源地震关系以及火山玄武岩地幔性质和长白山地热活动等资料并参考前人研究成果,建立了长白山地幔柱模型,对长白山火山地震活动机制进行了初步探讨。

The researches of volcanic earthquake activities recorded at Tianchi Volcano Observatory （TVO） since 1999 showed that the volcanic earthquake activities changed their features before or after the occurrence of the intermediate-deep earthquakes, magnitude 5.0 or larger than that, in the Northwestern Pacific Ocean. Our statistical data revealed the following three cases： the first one is that, the volcanic earthquakes became strengthening followed the deep earthquakes; the second is that, the intermediate-deep earthquakes took place after the volcanic earthquake swarm; and the third one is the volcanic earthquakes took place before or after the intermediate-deep earthquakes. That means that the intermediate or deep earthquakes happened while the volcanic earthquakes at Tianchi volcano became relatively less. In this paper, we present a Mt. Changbai mantle plume model and discuss a preliminary mechanism of the volcanic earthquake activities, by studying the recent volcanic earthquakes activities of Mt. Changbai and the intermediate-deep earthquakes of the Northwestern Pacific subducting plate, the feature of the basaltic mantle and the Mt. Chanbai geothermal activities, based on the former researchers achievements.