Abstract:In this paper, we calculate the ionospheric TEC disturbance caused by the 2015 MW7.8 Nepal earthquake and analyze the FFT spectrum based on GPS observation data to research temporal and spatial characteristics of earthquake ionospheric TEC. The results show that obvious abnormal disturbance appears 5 minutes after earthquake and lasts more than 6 minutes with a trend of increasing-decreasing-increasing. The disturbance propagates towards east, northeast and several directions, whose velocities are 2 336.36 m/s and 455.52-937.64 m/s. The center frequencies are mostly 3-7 mHz, which is consistent with the disturbance spectrum caused by Rayleigh wave and acoustic wave.