Name : WATANABE,  Hidefumi
            Position : Professor
            Division/Center : Volcano Research Center
            Research Area : Volcano Geophysics
 
 

research:

       My major research interests include physical mechanisms of volcanic activity, exploration of the subterranean structure of volcanoes,
       integrated research on the magma plumbing system, and their application to the prediction of volcanic eruptions. We clarified the
       mechanisms of the 1986-87 eruptions of Izu-Oshima volcano based on the results of extensive observation; ground deformation
       accompanied by volcanic tremors, electromagnetic changes associated with summit eruptions, gravity changes caused by fissure
       eruption and magma movement in the summit conduit. By integrating the precursors to the 1986 eruption, I proposed that the
       accumulation of magma had continued until 1980, and then the basalt magma started to rise up through the well-developed conduit.
       Since 1987 after the eruption, we have repeated the EDM and GPS measurements and revealed a re-inflation of the volcano, which
       suggesting a continuous magma supply from depths. We have developed new methods of diffraction tomography and density-velocity
       joint-inversion to achieve a higher resolution in the exploration of the subterranean structure of the volcano, and delineated a low
       velocity zone and a melt batch at the same location beneath the caldera as that of the inflation source. The magma plumbing system of
       Izu-Oshima volcano is characterized by a continuous magma supply and a well-developed conduit connecting the magma reservoir
       and the summit crater. The proposed model for the magma plumbing system might provide a basis for not only the short-term but also
       mid-term prediction of the future eruption of Izu-Oshima volcano. In addition to the above works, I have recently been promoting a
       project of 1km-deep scientific drilling within the caldera, at a distance of 1km from the summit crater, of Izu-Oshima volcano. The
       major aim is to conduct basic researches on the generating mechanisms of short-term precursors to the summit eruption, physical
       processes of magma-ground water interaction, subsurface structure, and geological study of the volcanic activity.

Publications:
Sasai, Y., J. Zlotnicki, Y. Nishida, M. Uyeshima, P. Yvetot, Y. Tanaka, H. Watanabe, and Y. Takahashi, Evaluation of electric and magnetic field monitoring of Miyake-jima volcano (Central Japan): 1995-1999, Annalidi Geofisica, 43, 2000 (in print).

Watanabe, H., Outlines of National Project for Prediction of Volcanic Eruptions, Reports on Volcanic Activities and Volcanological Studies in Japan for the Period from 1995 to 1998, 60--64, 1999.