Hi All. This may help to explain why at present time it is felt that earthquake prediction may not be possible. Keep in mind that this is based on today’s technology. Take Care…Don in creepy town.

Earthquakes Cannot Be Predicted

Robert J. Geller, David D. Jackson, Yan Y. Kagan, Francesco Mulargia, Ian Main

Ian Main

A useful earthquake prediction requires the location, time, and magnitude of a potentially damaging future event be specified in advance, within narrow limits. Further, the probability of occurrence of this prediction (within its stated error bounds) should be shown to be above the background level of random chance in the area of interest. If narrow limits or error bounds cannot be specified, then the resulting uncertainty precludes the practical possibility of an evacuation programme. If the null hypothesis of a random chance event cannot be excluded, then the prediction is not statistically significant. Given the inherently noisy nature of geophysical data, it is also important that data on failures is as easy to obtain as that on successes, including both 'misses' and 'false alarms'. Otherwise the selective publication of data may lead to a spuriously high statistical significance.

Robert J. Geller, David D. Jackson, Yan Y. Kagan, Francesco Mulargia

Is prediction inherently impossible or just fiendishly difficult? In practice, it doesn't matter. Scientifically, the question can be addressed using a Bayesian approach. Each failed attempt at prediction lowers the a priori probability for the next attempt. The current probability of successful prediction is extremely low, as the obvious ideas have been tried and rejected for over 100 years.

Systematically observing subtle phenomena, formulating hypotheses, and testing them thoroughly against future earthquakes would require immense effort over many decades, with no guarantee of success. It thus seems unwise to invest heavily in monitoring possible precursors.

Occasionally, scientists seem to have succeeded. On 3 February 1975 a swarm of small quakes struck Haicheng Province in Manchuria. Believing them to be precursors of some far more serious event, Chinese geophysicists issued a warning that a major quake would strike within the next two days. Sure enough, less than 24 hours later a major quake did strike, registering 7.3 on the Richter scale, but not before an evacuation had been carried out, allowing thousands of lives to be saved in the first successful prediction of a major quake.

Or was it? To this day, the events around the Haicheng earthquake prediction are surrounded by controversy, with skeptics claiming that it was little more than a coincidence. Their argument draws strength from the fact that the same Chinese team had made a prediction some months earlier, based on the same type of precursor ­ but that quake had failed to materialize. And whatever the supposed breakthrough made by the team, it failed to save the lives of the 240,000 who died in Tang Shan the following year, in what remains the most lethal earthquake to strike this century.

• Earthquakes Cannot Be Predicted