Earthquake Prediction

Robert Geller (Commentary, Feb. 2) reaches the conclusion “there are no reasonable prospects in the near future” for earthquake prediction. His statements that predictions up to now have failed, and that the majority of seismologists think that earthquakes cannot be predicted reliably and accurately, are correct but irrelevant. If efforts to find a cure for a disease have failed to date, and the majority of specialists do not see a solution, it does not follow that reasonable prospects for cure do not exist, whatever the time scale.

The assertion that we do not know the physical basis for reliable prediction is incorrect. We have known for decades that the requisite physics for prediction is the relationship between the stress in the earth and the critical threshold for fracture of rocks. However, the problem of understanding the relationship between the physics and the occurrence of earthquakes is difficult, and the solution to the puzzle is not likely to be a simple one. Physicists in this field have been correctly cautious about making unjustifiable predictions.

Geller’s conclusion is correct; a more appropriate statement is that the prospects are reasonable in the long term but much hard work lies ahead.

LEON KNOPOFF, Professor

Geophysics and Physics, UCLA