Investigation of ionospheric response due to Tohoku earthquake using GPS satellite measurements

This paper investigates the ionospheric response due to the great M 9.0 Tohoku earthquake on 11 March 2011 in Japan using ground-based GPS-TEC measurements surrounding the epicenter. Results show that co-seismic TEC oscillations were observed starting from 7-14 minutes after the earthquake with typical periods of 2-7 minutes, peak disturbance time lag of 13-17 minutes. Results show that the short period ionospheric disturbances induced by acoustic waves travelling in the ionosphere and Rayleigh waves propagate at horizontal velocities of about 1212 m/s and 2216 m/s, respectively. These short period ionospheric disturbances were observed in the northeast direction of the epicenter.