Neural network based tomographic approach to detecting the ionospheric anomalies prior to the 2007 Southern Sumatra earthquake

In this paper, neural network based ionospheric tomography was performed to investigate the detailed structure that may be associated with earthquakes. The 2007 Southern Sumatra earthquake (M8.5) is selected because significant decreases in the Total Electron Content (TEC) have been confirmed by GPS data analysis. With respect to the analyzed earthquake, we detected significant decreases at heights of 250-400 km, especially at 300 km. The global tendency is that the decreased region expands to the east with increasing altitude and concentrated in the Southern hemisphere over the epicenter. Furthermore, obtained results are consistent with other satellite observation.