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Volume 17: Number 1: Article 3
Rocks That Crackle and Sparkle and Glow: Strange Pre-Earthquake Phenomena
Friedemann T. Freund, Department of Physics, San Jose State University;
NASA Ames Research Center, Moffett Field, CA 94035-1000
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.
Keywords: earthquakes, pre-earthquake phenomena, earthquake prediction,
defects in minerals, positive holes, ground currents, ground potentials,
corona discharges, ion emission, electromagnetic emissions, magnetic
anomalies, earthquake lights, thermal anomalies, ionosphere
FULL TEXT:
Rocks That Crackle and Sparkle and Glow: Strange Pre-Earthquake Phenomena
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