Affiliation: | Earthquake Research Institute, University of Tokyo, 1-1-1;Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan. E-mail: Geoelectromagnetic Research Institute, Russian Academy of Sciences, 142190,;Troitsk, Moscow region, Russia Danish Space Research Institute, Juliane Maries Vej, 30, DK-2100;Copenhagen, Denmark Japan Marine Science and Technology Center, Natsushima, 2-15,;Yokosuka, 237-0061, Japan |