Monday, September 26, 2011

Radon predicting Earthquakes

April 07, 2009"Being able to predict earthquakes is the Holy Grail of seismology," Caltech seismologist Egill Hauksson said. "The more we try, the less progress we seem to make.
a scientist little known in earthquake circles made a bold prediction of a destructive earthquake in the Abruzzo region of central Italy based on spikes in radon gas. Giampaolo Giuliani went so far as to tell the mayor of a town there that it would strike within the next 24 hours.
His deadline passed and for days, nothing happened.
Then, early Monday, a magnitude-6.3 earthquake struck near the town of L'Aquila, sparking a controversy around the world about whether Giuliani truly predicted the temblor or whether it was a fluke of timing.
Mar 18, 2010 a group of physicists, led by physics Nobel laureate Georges Charpak, has developed a new detector that could measure one of the more testable earthquake precursors – the suggestion that radon gas is released from fault zones prior to earth slipping.
elevated concentrations of radon gas in soil or groundwater could be the sign of an imminent earthquake. It is believed that the radon is released from cavities and cracks as the Earth's crust is strained prior to the sudden slip of an earthquake. In order to test this hypothesis, however, researchers would need to deploy several hundred detector devices along a fault zone.
Charpak's alternative detector is based on established technology already in action in extreme conditions at laboratories such as CERN. It consists of a wire-type counter, which is the concept for which Charpak won his Nobel prize in 1992. In these devices, particles such as radon enter a gas-filled container and ionize some of the gas particles. The resulting ions and electrons are accelerated by a potential on the wire, causing a cascade of ionization that results in a current in the wire.

One key feature of this new detector design is that it works with ambient air, thus avoiding the need to keep refilling the detector's ionization chamber with a particular gas. It also has a high efficiency, which was achieved by including multiple wires in the ionization chamber. In laboratory tests, the researchers report a radon count of 140 Bq.m–3 over one minute, which is comparable to that offered by commercial devices. The tests also show that the device still functions in 70% humidity,

FEBRUARY 07, 2007

it has been known for a while that radon levels in the atmosphere can correspond to tectonic activity. Direct measurements of radon levels have shown large fluctuations immediately preceding earthquakes. What this paper presents is the idea that instead of a direct measurement of radon levels, remotely sense temperature and humidity measurements can be used as a proxy for the same phenomena. When Radon in the air decays, it ionizes other nearby molecules or atoms. These newly formed ions are then hydrated by atmospheric water, with the result that air humidity drops. The latent heat of evaporation is released from the water during the phase transformation, which results in a temperature increase. So, big pulses of Radon into the atmosphere, as are associated with tectonic activity and seem to occur leading up to earthquakes, results in an initial decrease in humidity and increase in temperature. The radon flux reaches a maximum and starts to decrease just prior to the "seismic shock", during which time there is a corresponding rise in humidity and drop in temperature.

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