Abstract

Seismic waves are the most dramatic and most intensely studied manifestations of earthquakes. However, we also know of non-seismic phenomena, which precede large earthquakes. Some of them have been reported for centuries, even millennia. The list is long and diverse: bulging of the Earth's surface, changing well water levels, ground-hugging fog, low frequency electromagnetic emission, earthquake lights from ridges and mountain tops, magnetic field anomalies up to 0.5% of the Earth's dipole field, temperature anomalies by several degrees over wide areas as seen in satellite images, changes in the plasma density of the ionosphere, and strange animal behavior. Because it seems nearly impossible to imagine that such diverse phenomena could have a common physical cause, there is great confusion and even greater controversy. This explains why reports on nonseismic pre-earthquake phenomena are regarded with suspicion in the scientific community. This may change with the recent discovery that igneous and metamorphic rocks, which make up a major portion of the Earth's crust, contain electric charge carriers, which have been overlooked in the past. These charge carriers are defect electrons in the valence band, i.e., positive holes. Under normal conditions they are dormant, but when they ??wake up'', the rocks begin to sparkle and glow. This paper describes the physical and chemical nature of these positive holes, how they are introduced into minerals and rocks, and how they become activated. Evidence will be presented that, once the positive holes are generated, currents propagate through the rocks leading to electromagnetic emission, to positive surface potentials, to corona discharges, to positive ion emission, and to mid-infrared radiation. These phenomena are expressions of the same fundamental process: the ??awakening'' of dormant positive hole charge carriers that turn rocks momentarily into p-type semiconductors.