Ionosphere quasistatic electric fields disturbances over seismically active regions as inferred from satellite-based observations: A review

The paper presents a review of studies on ionosphere quasi-static electric fields’ variations over seismically active regions. It also highlights the urgency of such review nowadays. The principle features of the considered disturbances are reported according to the INTERCOSMOS-BULGARIA-1300 and DEMETER satellites observations. The electrostatic disturbances take place in all (E x , E y , E z ) components of the ionosphere electric field vector, happen over the near-epicenter as well as magnetically conjugated regions and are observed from a few minutes to a few tens of hours before and after a seismic event. They are 1–26 mV/m in amplitude and 1°–20° in space. Paper also reports nighttime domination of the considered disturbances and their amplitudes dependencies on the earthquake magnitude as well as hypocenter depth.