Babak Haghighi - Dept. of Physics, Faculty of Science, Islamic Azad University, mashhad Branch, mashhad,Iran

Prior to large earthquakes the Earth sends out transient signals, sometimes strong, moreoften subtle and fleeting. These signals may consist of local magnetic field variations,electromagnetic emissions over a wide range of frequencies, a variety of atmospheric andionospheric phenomena. Great uncertainty exists as to the nature of the processes thatcould produce such signals, both inside the Earth’s crust and at the surface. The absenceof a comprehensive physical mechanism has led to a patchwork of explanations, whichare not internally consistent. Fround marked on the theory that most crustal rocks containdormant electronic charge carriers in the form of peroxy defects, O۳Si=OO n SiO۳, holdsthe key to a deeper understanding of these pre-earthquake signals .When rocks arestressed, peroxy links break, releasing electronic charge carriers, h_, known as positiveholes. The positive holes are highly mobile and can flow out of the stressed subvolume.The situation is similar to that in a battery. The h_ outflow is possible when the batterycircuit closes. The h_ outflow constitutes an electric current, which generates magneticfield variations and low frequency EM emissions. The study of chemical processes basedon a model equation for electromagnetic waves is presented.

Electromagnetic waves, pre earthquake, tectonic