Seismic activity as a source of the ionospheric variability

Abstract Ionospheric variations, observed mainly by vertical sounding technique, over the seismically active regions are interpreted in terms of lithosphere-ionosphere coupling. The methods of identification of variations induced by seismic activity within the ionosphere are proposed. It is shown that such variations have their individual features, different from variations induced by magnetic disturbances and other kinds of external activity. The magnitude and occurrence of such variability lead to conclusion that seismic activity is important source of the ionospheric variability.