The method tries to assess electromagnetic emissions that, according to the VAN team, occur several days to hours before the earthquake and can be interpreted as warnings for a forthcoming catastrophe. The method uses a network of metal rods impacted in the ground. Electromagnetic signals picked up by the rods are then processed to filter out noise and the so-called "seismic signals", thought to result from piezoelectric phenomena as material in the earth's mantle is subject to changing pressures preceding an earthquake, are identified. One inherent problem of the method is that, in order for any prediction to be useful, it has to predict a forthcoming earthquake with a reasonable accuracy with respect to timeframe, epicenter and magnitude. Otherwise, if the prediction is too vague, no feasible decision (such as to evacuate the population of a certain area for a given period of time) can be made. The VAN team have been arguing that, as the sensor rod network expands and its data processing technique is refined, its predictions will become increasingly useful.
The efficiency of the VAN method in earthquake prediction is a matter of debate, as a number of prominent seismologists have disputed its accuracy. One of the major opponents of VAN is the Greek seismologist Vassilis Papazachos. The debate between Papazachos and the VAN team has repeatedly caused public attention in their home country Greece and has been extensively discussed in the Greek media. As Greece is highly seismogenic and has suffered major disasters by earthquakes, the Greek public is extremely concerned over this debate.
Quake prediction tool gains ground. (electromagnetic changes in the crust used to predict earthquakes)(Research News)
Nov 10, 1995; Seismologists don't fully understand a controversial Greek prediction scheme, and some think its "successes" are just luck. But...