Affiliation: | Instituto de Geofisica, Universidad Nacional Autónoma de México, Del. Coyoacan, 04510, México D.F., México,;Department of Earth Sciences, School of Science, Ehime University, Bunkyo-cho 2–5, Matsuyama 790–8577, Japan,;Geophysical Service, Academy of Sciences of Russia, Piip Avenue 9, Petropavlovsk-Kamchatsky, 683006, Russia |