Fig. 1.From: Ionospheric multiple stratifications and irregularities induced by the 2011 off the Pacific coast of Tohoku EarthquakeIonospheric signature prior to the earthquake. The map in the center shows the TEC disturbance (Tsugawa et al., 2011) and the four ionograms are for Kokubunji (bottom right), Wakkanai (top right), Yamagawa (top left), and Okinawa (bottom left) in the order of distance from the epicenter.Back to article page