VOLCANIC EARTHQUAKE ANALYSIS OF THE YASUR VOLCANO, TANNA ISLAND, VANUATU
Supervisor: Yuchi NISHIMURA
Volcanic earthquakes are related to magmatic processes. For the Yasur volcano, Tanna Island Vanuatu, which is permanently active, its Strombolian activity is observed and studied during high activity period. Three main groups of volcanic earthquakes were identified, according to their arrival time difference between the two observation stations and their dominant frequency, the intermediate frequency, the low frequency and the typical explosion earthquakes. Within the low frequency earthquakes, three types of similarities were identified, the YI type with dominant frequency between 1 Hz and 2 Hz; the YII type with the uniform amplitude and dominant frequency of 1.2 Hz and the YIII type with the dominant frequency of 1.5 Hz. The explosions earthquakes show a long duration between the two phases arrival time indicating the time of transportation of gas bubbles in the conduit from their formation location to the surface.
|Citation: ||Bulletin of IISEE, 42, 55-60.|