マグマ溜まりから火山噴煙 : 観測と数理モデル

抄録

Integrating multiple observations and mathematical modeling plays a key role in understanding dynamics of volcanic eruptions. In particular, this integration is important for magma ascent process in the conduit (i.e., conduit flow), because this process strongly controls diversity of eruption styles, whereas the direct observations of the process are lacking. In this paper, I investigated the relationship between the recent conduit flow model and multiple observations, especially focusing on how parameters and variables in the conduit flow model are constrained from the observations. Results show that most of the parameters and variables are well constrained by some observation methods, and that pressure changes in the magma chamber and the conduit obtained from the conduit flow model are important variables utilized for detecting eruption transitions from geodetic observations. In the 1995-2010 eruptions of Soufrière Hills volcano, conduit flow models were well combined with observation data, in which a key variable connecting models and observations was the period of cyclic behavior during lava dome eruptions. Recent observations for the 2011 eruptions of Kirishima-Shinmoe-dake volcano indicate that high-resolution measurements of subsurface and surface phenomena enable us to obtain more detailed information on eruption dynamics, which may promote development of a more advanced mathematical model.