Last Update 04/06 2007
Research: (1) Study of electrical conductivity distribution within the Earth from global to local scales. (2) Observation of the geomagnetic and geo-electric field by a network of magnetic stations and submarine cables (3) Ocean bottom electromagnetic observations (4) Study of dynamics in the core and the core-mantle interaction (5) Development of modeling tools for the electromagnetic induction methods (6) Development of a variety of electromagnetic observation instruments (7) Study of volcanic activities by electromagnetic methods (8) Study of seismo-electromagnetic phenomena Publications: Utada, H., On the physical background of the VAN earthquake prediction method, Tectonophysics, 224, 153--160, 1993. Utada, H., T. Yoshino, T. Okubo, and T. Yukutake, Seismic resistivity changes observed at Aburatsubo, central Japan, revisited, Tectonophysics, 299, 317--331, 1998. Utada, H., M. Neki, and T. Kagiyama, A study of annual variations in the geomagnetic total intensity with special attention to detecting volcanomagnetic signals, Earth Planets Space, 52, 91--103, 2000. Utada, H., and H. Munekane, On galvanic distortion of regional three-dimensional magnetotelluric impedances, Geophys. J. Int., 140, 2, 385--398, 2000. Ogawa, T, and H. Utada, Coseismic piezoelectric effects due to a dislocation 1. An analytic far and early-time field solution in a homogeneous whole space, Phys. Earth Planet. Inter., 121, 273--288, 2000. Koyama, T., H. Shimizu, and H. Utada, Possible effects of lateral heterogeneity in the D'' layer on electromagnetic variations of core origin, Phys. Earth Planet. Inter., 129, 99--116, 2002. Utada, H., Koyama, T., Shimizu, H., and Chave, A. D, A semi-global reference model for electrical conductivity in the mid-mantle beneath the north Pacific region, Geophys. Res. Lett., 30, 4, doi:10.102--1194, 2003. Utada, H., Interpretation of time changes in the apparent resistivity observed prior to the 1986 eruption of Izu-Oshima volcano, Japan, J. Volcanol. Geotherm. Res., 126, 97--107, 2003. Fukao, Y., T. Koyama, M. Obayashi, and H. Utada, Trans-pacific temperature field in the mantle transition region derived from seismic and electromagnetic tomography, Earth Planet. Sci. Lett., 217, 425--434, 2004. Shimizu, H., and H. Utada, The feasibility of using decadal cahnges in the geoelectric field to probe Earth's core, Phys. Earth Planet. Inter., 142, 297--319, 2004. Koyama, T., H. Shimizu, H. Utada, M. Ichiki, E. Ohtani, and R. Hae, Water Content in the Mantle Transition Zone Beneath the North Pacific Derived From the Electrical Conductivity Anomaly, AGU Geophys. Monogr. Ser., 168, 171--179, 2006. |
