Abstract: The seismic intensity at the Tianchi volcano has increased obviously since June, 2002. In this paper, we introduce the characters of the seismic activity at Tianchi volcano based on the seismic data recorded at the Tianchi Volcano Observatory (TVO). It shows that since 1999 the seismic activity mainly belongs to the tectonic event based on a seismic spectral and time frequency analysis. We examine the coda Q values of these earthquakes and compare them with the data from Sichuan district, and find that the coda Q value from Changbaishan is lower than that in Sichuan, indicating that the level of the tectonic activity in the researched Changbaishan area is relatively high.

Key words: Tianchi volcano, volcanic earthquakes, seismic spectral analysis, coda Q values

摘要： 2002年6月以来,长白山天池火山区的地震活动明显增强。利用长白山火山中心站的观测资料对长白山天池火山地震的活动特征进行了研究。火山地震的频谱分析和时频分析结果表明,自1999年以来发生的火山地震主要为构造型火山地震。对这些火山地震进行了尾波Q值分析并与四川地区的Q值进行了对比,结果表明长白山火山区尾波Q值偏低,说明这一地区构造活动水平相对较强。

关键词: 天池火山, 火山地震, 频谱分析, 尾波Q值