  The paper presents the three-dimensional structure of the ionospheric
electron density disturbances triggered by the vertical electric currents
flowing between the Earth and ionosphere over the faults before the strong
earthquakes. The results were obtained using the global numerical Earth's Upper
Atmosphere Model (UAM). The vertical electric currents flowing between the
Earth and ionosphere over the faults were used as lower boundary conditions for
the UAM electric potential equation. The UAM calculated 3D structure of the
ionospheric electron density disturbances demonstrates an importance of all
three ionospheric plasma drift directions (movements) - vertical, meridional
and zonal but not only vertical one.
