This book discusses how the increased emanation of radon and other gases from the Earth’s crust in the vicinity of active tectonic faults triggers a chain of physical processes and chemical reactions in the atmospheric boundary layer and the Earth’s ionosphere over an earthquake area several days/hours before strong seismic shocks occur. It presents the two main concepts involved in this mechanism: atmosphere ionization and the global electric circuit. The Lithosphere-Atmosphere-Ionosphere Coupling (LAIC) concept is strongly supported by experimental data showing the atmospheric and...