Last Update 11/06 2014
Research: (1) Modeling of physical processes in magma chambers (e.g., magma mixing, crystallization) to understand the evolution of volcanoes and the diversity of volcanic rocks. (2) Numerical modeling of magma ascent in volcanic conduits and dynamics of eruption clouds to understand the diversity of eruption styles and transition mechanisms of the eruption styles. Publications: T. Koyaguchi, Magma mixing in a conduit., J. Volcanol. Geothem. Res., 25, 365--369, 1985. T. Koyaguchi, Life-time of a stratified magma chamber recorded in ultramafic xenoliths from Ichinomegata volcano, northeastern Japan., Bull. Volcanology, 48, 313--323, 1986. T. Koyaguchi, Evidence for two-stage mixing in magmatic inclusions and rhyolitic lava domes on Niijima Island, Japan., J. Volcanol. Geothem. Res., 29, 71--98, 1986. T. Koyaguchi , Magma mixing in a squeezed conduit., Earth Planet. Sci. Lett., 84, 339--344, 1987. T. Koyaguchi, S. Blake, The dynamics of magma mixing in a rising magma batch., Bull. Volcanology, 52, 127--137, 1989. T. Koyaguchi, Chemical gradient at diffusive interface in magma chambers., Contrib. Mineral. Petrol., 103, 143--152, 1989. T. Koyaguchi, M. A. Hallworth, H. E. Huppert, R. S. J. Sparks, Sedimentation of particle from a convecting fluid., Nature, 343, 447--450, 1990. T. Koyaguchi, M. Tokuno , Origin of the giant eruption cloud of Pinatubo, June, 1991., J. Volcanol. Geotherm. Res., 55, 85--96, 1993. T. Koyaguchi, M. A. Hallworth and H. E. Huppert, An experimental study on the effects of phenocrysts on convection in magmas., J. Volcanol. Geotherm. Res., 55, 15--32, 1993. A. W. Woods, T. Koyaguchi, Transitions between explosive and effusive eruptions of silicic magmas., Nature, 307, 641--644, 1994. T. Koyaguchi, Grain-size variation of the tephra derived from umbrella clouds., Bull. Volcanol., 56, 1--9, 1994. T. Koyaguchi, A. Takada, An experimental study on the formation of composite intrusions from zoned magma chambers., J. Volcanol. Geotherm. Res., 59, 261--267, 1994. T. Koyaguchi, Volume estimation of the ejecta of Pinatubo 1991 eruption by means of fluid dynamics model and geological methods., Fire and Mud, Monograph of the Pinatubo 1991eruption, 583--600, 1996. T. Koyaguchi, A.W. Woods , On the formation of eruption columns following explosive mixing of magma and surface-water., J. Geophys. Res., 23, 5561--5574, 1996. S. Yoshida, T. Koyaguchi, A new regime of volcanic eruption due to the relative motion between liquid and gas., J. Volcanol. Geotherm. Res., 89, 303--315, 1999. T. Koyaguchi, K. Kaneko, A two-stage thermal evolution model of magma in continental crusts., J. Petrol., 40, 2, 241--254, 1999. T. Koyaguchi, K. Kaneko, Thermal evolution of silicic magma chambers after basalt replenishments., Trans. Royal Soc. Edinburgh, 91, 47--60, 2000. T. Koyaguchi, M. Ohno, Reconstruction of eruption column dynamics on the basis of grain-size of tephra-fall deposits: Part 1. Methods., J. Geophys. Res., 106, 6499--6512, 2001. T. Koyaguchi, M. Ohno, Reconstruction of eruption column dynamics on the basis of grain-size of tephra-fall deposits: Part 2. Application to the Pinatubo 1991 eruptions., J. Geophys. Res., 106, 6513--6533, 2001. K. Kaneko, T. Koyaguchi, Experimental study on the effects of crustal temperature and composition on assimilation with fractional crystallization at the floor of magma chambers., J. Volcanol. Geotherm. Res., 129, 155--172, 2004. T. Koyaguchi, N. K. Mitani, A theoretical model for fragmentation of viscous bubbly magmas in shock tubes, J. Geophys. Res., 110, doi:10.102, , 2005. T. Koyaguchi, An analytical study for 1-dimensional steady flow in volcanic conduits, J. Volcanol. Geotherm. Res., 143, 29--52, 2005. Y. J. Suzuki, T. Koyaguchi, M. Ogawa, I. Hachisu, A numerical study of turbulent mixing in eruption clouds using a three-dimensional fluid dynamics model, J. Geophys. Res., 110, doi:10.102, , 2005. M. Nakanishi, T. Koyaguchi, A stability analysis of a conduit flow model for lava dome eruptions., J. Volcanol. Geotherm. Res., 178, 46--57, 2008. T. Koyaguchi, B. Scheu, N. K. Mitani, O. Melnik, A fragmentation criterion for highly viscous bubbly magmas estimated from shock tube experiments, J. Volcanol. Geotherm. Res., 178, 58--71, 2008. T. Kozono, T. Koyaguchi, Effects of relative motion between gas and liquid on 1-dimensional steady flow in silicic volcanic conduits: 2. origin of diversity of eruption styles, J. Volcanol. Geotherm. Res., 180, 37--49, 2009. T. Koyaguchi, K. Ochiai, Y. J. Suzuki, The effect of intensity of turbulence in umbrella cloud on tephra dispersion during explosive volcanic eruptions: Experimental and numerical approaches, J. Volcanol. Geotherm. Res., 186, 68--78, 2009. Y. J. Suzuki, T. Koyaguchi, A three-dimensional numerical simulation of spreading umbrella clouds, J. Geophys. Res., 114, B03209 doi:10.1029/2007JB005369, , 2009. T. Kozono, T. Koyaguchi, Effects of relative motion between gas and liquid on 1-dimensional steady flow in silicic volcanic conduits: 1. an analytical method, J. Volcanol. Geotherm. Res., 180, 21--36, 2009. T. Koyaguchi, Y. J. Suzuki, T. Kozono, Effects of the crater on eruption column dynamics, J. Geophys. Res., 115, B07205, doi:10.1029/2009JB007146, , 2010. T. Kozono, T. Koyaguchi, A simple formula for calculating porosity of magma in volcanic conduits during dome-forming eruptions, Earth Planets Space, 62, 483--488, 2010. Y. J. Suzuki, T. Koyaguchi, 3-D numerical simulations of eruption column collapse: effects of vent size on pressure-balanced jet/plumes, J. Volcanol. Geotherm. Res., 221-222, 1--13, 2012. T. Kozono, T. Koyaguchi, Effects of gas escape and crystallization on the complexity of conduit flow dynamics during lava dome eruptions, J. Geophys. Res., 117, doi:10.1029/2012JB009343, , 2012. T. Kozono, H. Ueda, T. Ozawa, T. Koyaguchi, E. Fujita, A. Tomiya, Y. J. Suzuki, Magma discharge variations during the 2011 eruptions of Shinmoe-dake volcano, Japan, revealed by geodetic and satellite observations., Bulletin of Volcanology, 75, DOI 10.1007/s00445-013-0695-4, , 2013. 小屋口剛博, 火山と噴火のダイナミックス，「地球惑星科学 第8巻 （平朝彦・末広潔・廣井美邦・巽好幸・高橋正樹・小屋口剛博・嶋本利彦 共著）」, 岩波書店, 1997. 小屋口剛博, 火山現象のモデリング, 東京大学出版会, 2008. |
