Quakes: when and where?
Till date, there were no truly "reliable" methods of quake prediction. Most of the existing methods predicted quakes only a short time before they actually occurred. But recently, Panayiotis Varotos from the University of Athens developed a technique that can predict earthquakes weeks in advance. Using changes in electrical conductivity (caused by the tectonic movements) and monitored by electrodes, Varotos claims to have measured voltage differentials of the order of 10 millivolts/km over distances of 100 km. He has also conducted research on similar electrical changes occurring within a crystal with dislocations and defects, and claims that the results are consistent (Journal of Applied Physics , Vol 83, 1998).