IS THE ION COMPOSITION OF THE OUTER IONOSPHERE RELATED TO SEISMIC ACTIVITY

In analyzing the ion composition data from the low-altitude Intercosmo s 24 satellite, significant longitudinal deviations in the latitudinal density variation of light ions, H+ and He+, were observed in the inn er plasmasphere at altitudes of 2000-2500 km. These deviations display surprising correlation with the seismic activity in the Earth's crust . H+ and He+ concentrations significantly enhanced with respect to val ues observed above seismically inactive regions were found above the e picenters of future earthquakes for up to two days before shocks. Thes e findings indicate that, at least under some conditions, processes of the coupling between the solid Earth and the ionosphere may be indica ted by in situ measurements of plasma parameters in the Earth environm ent.