Radon's flow within the earth's crust could offer seismologists clues about the magnitude of an impending earthquake, according to a model proposed by Robert L. Fleischer, a General Electric Company physicist, at the AGU Fall Meeting last month. His work suggests that an extensive network of radon monitoring stations would be useful for early warning of potential damage areas of the pending tremors.
Small amounts of radon, a gas released by the decay of uranium, tends to move slowly within the earth's crust where rocks are relatively porous. Velocities of a few inches an hour are typical. Shifting stresses in the earth's crust that precede an earthquake can speed up or slow down radon's movements.