Assessing ionospheric activity from GNSS measurements as a possible precursor of high magnitude earthquakes

The Lithosphere-Atmosphere-Ionosphere Coupling model provides for the modification of atmospheric physical properties prior to a high magnitude earthquake over an area near to the epicentre. Ionization of air, caused by possible radon leaking from earth crust, could be one of the causes. In the GNSS (Global Navigation Satellite System) sciences, disturbances of ionospheric activity can be investigated through the analysis of refraction phenomena occurring on the signal along the path satellite-to-receiver and maps representing the ionospheric activity as Total Electron Content could be drawn. By a 6 month long series of GNSS data, we investigated ionospheric disturbances related to the M=6.3 earthquake occurred at L’Aquila (Italy) on 6th of April 2009. Resulting TEC maps exhibit meaningful anomalies 3 weeks before the main shock.