11:00 AM - 11:15 AM
[MTT49-02] Propagation of infrasound generated by an explosive eruption of Mt. Shinmoedake on 10 March 2018
Keywords:infrasound, ray tracing, volcanic eruption
We developed a new formulation for three-dimensional wave propagation in a stratified atmosphere and apply it to the analysis of the detected signals. The present formulation is based on the dispersion relation of the wave, which corresponds to Hamiltonian in particle mechanics, and Hamilton equations describing time variations of group velocity of the wave and wavevector. We adopt the dispersion relation ω = csk +u・k, where ω is angular frequency of the wave, cs is sound speed, k is the wavevector, and u is wind velocity. Using the vertical temperature profiles provided by NRL-MSISE00(Picone et al., 2002) and the zonal and meridional wind profiles by HWM14 (Drob et al., 2015), we made ray tracing of the waves emitted at the explosive eruption observed on 10 March 2018. We show results of the ray tracing calculations and compare them with the signals detected by our infrasound sensors deployed in Shikoku Island(see the figure). Discussion is given on the origin and nature of the observed signals.