Preliminary results from seismic monitoring at the Tatun Volcanic area of northern Taiwan

To enhance our understanding of the seismic characteristics of the Tatun volcanic area, a small aperture seismic array consisting of 5 seismic stations has been deployed in the area since May 2003. Each of the seismic stations was installed with both short-period and broadband sensors to record micro-earthquakes as well as long-period volcanic tremors. The preliminary results of the seismic monitoring of the Tatun volcanic area show a large number of shallow micro-earthquakes clustered beneath the Chihsingshan volcano and Tayoikeng areas. Among these, some swarms were also detected. Intensifying the issue further, some complex seismograms with harmonic codas and seismic tremors have been identified. Considerable crustal heterogeneity in the Tatun volcanic area is indicated by the presence of strong coda waves. Combining our findings with other geological and geochemical observations, we postulate that volcanic activities might not be totally extinct in the Tatun volcanic area. Thus, further investigations of Tatun volcanic area ought be conducted to examine the possibility of such potential volcanic activity.