http://www.virginia.edu/uvatoday/newsRelease.php?id=16666Study: Ozone From Rock Fracture Could Serve As Earthquake Early Warning
November 16, 2011 — Researchers the world over are seeking reliable ways to predict earthquakes, focusing on identifying seismic precursors that, if detected early enough, could serve as early warnings.
New research, published this week in the journal Applied Physics Letters, suggests that ozone gas emitted from fracturing rocks could serve as an indicator of impending earthquakes. Ozone is a natural gas, a byproduct of electrical discharges into the air from several sources, such as from lightning, or, according to the new research, from rocks breaking under pressure.
Scientists in the lab of Raúl A. Baragiola, a professor of engineering physics in the University of Virginia School of Engineering and Applied Science, set up experiments to measure ozone produced by crushing or drilling into different igneous and metamorphic rocks, including granite, basalt, gneiss, rhyolite and quartz. Different rocks produced different amounts of ozone, with rhyolite producing the strongest ozone emission.
Some time prior to an earthquake, pressures begin to build in underground faults. These pressures fracture rocks, and presumably, would produce detectable ozone.
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http://dx.doi.org/10.1063/1.3660763