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.
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,