Seismic Monitoring of Volcanic Evolution, a Case Study in Jeju Island, South Korea.

During the volcanic evolution, the gas and magma composition in the medium change with time, which may lead temporal variations in characteristics of seismic waves. This feature may allow seismic monitoring of the volcano using the seismic velocity measurements. However, the influence of the changes in the medium composition on the seismic velocities is not identified quantitatively. Numerical simulation is a useful tool to find the relationship between physical properties of rock and fluid with the properties of propagating wave. In current work, we developed a numerical simulation scheme to measure the influence on wave characteristic propagating through a volcanic region. Through the numerical simulation we will measure the influence on the Vp and Vs velocities of a wave propagating through a volcanic region with varying saturation which will lead us to measure the Vp/Vs ratios by which the actual state of volcano will be identified. Then from the real data of local earthquakes the P and S travel times will be measure which will help us to measure the Vp/Vs. In order to authenticate our results, the numerically calculated results will be compared with the results measured from the real seismic data. The findings from this work will help us to precisely interpret the actual state of the volcano at that time and to mitigate the volcanic hazards timely.