Monitoring of Crustal Activities in Southwestern Taiwan(III)

Monitoring of Crustal Activities in Southwestern Taiwan(III)

Due to complicated geographic and geological conditions, southwestern(SW) Taiwan has suffered from various natural disasters over the years, and is especially at risk of earthquakes, caused by the collision of two tectonic plates. Historically, big earthquakes occurring in this area have often caused serious damage. Therefore, it is necessary and important to understand the relationship between seismic activity and seismogenic characteristics around this area. This study utilizes a high-density seismic network to monitor crust activity beneath the study area. The physical properties of crust exhibit variation due to the effect of tectonic stress, especially before and after strong earthquakes. The relevant physical parameters(velocity, attenuation) undergo a change, as has been mentioned in numerous studies. Therefore, this study analyzes the relocated seismicity, focal mechanisms, and seismic b-value to assess the seismic potential. The obtained variation in physical parameters confirms the correlation between the observed data and earthquakes, and assesses whether changes in the regional stress state have occurred. The results not only give a better understanding of the seismogenic structure beneath SW Taiwan, but also allow us to identify physical characteristics caused by the seismic activity and mountain building processes.