Abstract
1 Abstract The electromagnetic radiation processes guiding the seismic activity before the earthquake has been occurred are given in this paper. The radiation processes are related to the structure of fault. The fault structures are modelled as suitable aperture antenna generating the electromagnetic radiation. This antenna is constructed with fractal arrays. The results are suitable to classify several seismic activities. There exist several sources generating electromagnetic waves on the earth [1] beside the electromagnetic phenomena in the geo-dynamo. The induction mechanisms generate surface currents and charges on the surfaces of the fault due to these electromagnetic sources [2]. The deviations of all the plate structure of the earth due to seismicity impress these surface currents to generate electromagnetic wave variations with ultra extra low ‐ ultra low - extra low ‐ low - audio frequencies (UEUELAF). The frequency spectrum of these seismicity related and seismicity modulated waves is within the frequency range from 0 Hz to 2 kHz around the active earthquake zones. This frequency range goes up to 12 GHz for the phenomena occurred over the active zone by the propagation chains in the ionosphere. The deviation characteristics in this class of some faults are considered and the electromagnetic radiation coming from fault modelled fractal antenna arrays due to these deviations are simulated in some fault zones. The region of sudden, non-smooth, and non-uniform change of electric charges coincides with possible source of waves (SE), to threshold a suitable mechanism triggering