Abstract
Phenomenon of volcanic eruption is occurred when high-pressure and high-viscous magma rapidly decompressed.Magma produces bubbles when it is decompressed,and explosive volcanic eruption is caused by the fragmentation of bubbly magma.In a previous study,although behavior of discharge flow is observed at low pressure condition,there are few knowledge at high pressure conditions.Also there are not so much research of the simultaneous measurement bubble generation and discharge flow.In this study,in order to understand relation between bubble generation and discharge flow in decompressing,we observe the two phenomena using two high-speed video cameras simultaneously.Its flow velocity is affected by pressure and viscosity.Discharge flow is suggested to occur to coincide with a time when diaphragm is broken.And bubble generation occurs the after discharge flow.
