Sunday, May 3, 2009

Stavros Tassos Replies To Geologist


Although I refrain answering to anonymous letters, I do it because you express your opinion in a legitimate way. Nevertheless I would prefer to address you in person.

Relevant to the issue and the possibility of earthquake prediction, actually there are two aspects: The purely scientific aspect, and the aspect of practical applicability.

As for the scientific aspect anyone who is involved in earthquake and earthquake prediction research knows that the problem of the physics of the earthquake source is not solved yet. On the other hand observation shows that earthquakes require concentration of energy in space and time, and that the earthquake is a quantized phenomenon, i.e., unless the necessary quantity of energy is provided, equivalent to the ~2´10^6 Joules/kg of latent energy the earthquake cannot occur, the same way boiling cannot occur; and the temperature of boiling water is 100 degrees Celsius, no matter the amount of boiling water is 1 gram, 1 kg or 1000 tons. Similarly the intensity of ground motion at the epicentral point is magnitude independent. That being so means that at these boundary conditions the phenomenon is time and space scale independent. It might never occur in a large spatial scale, or the whole process might be completed within seconds, if it does occur; the two extremes being by far the most usual cases. This by no mean means that determinism is lost; it means that as in the unit circle the functions of an angle are absolutely deterministic, all points are equally possible within the limits of the unit circle, the radius of which in the case of mid-term earthquake prediction is ~150 km. In other words an earthquake, as a wave, is a chaotic but not an arbitrary function.

It is also known that there are about 400 precursors, among which radon emissions are probably one of the most promising, along with dilatancy, changes in the electromagnetic field etc. But taking into consideration the previously mentioned deterministic uncertainty (odd as it may sound), it means that you might have this and other precursors and the strong earthquake never occur, or it may occur even within seconds after the detection of these precursors.

Furthermore the mainstream plate tectonics, elastic rebound and static stress context misdirects thought and asks the wrong questions, thus giving the wrong answers, e.g., earthquakes being a result of horizontal motion of plates.

And now we come to the practical applicability aspect of earthquake prediction. Taking for granted that all rules of the scientific method have been followed, and given that the area is more or less well determined if there is a previous earthquake activity (in the case of the L’Aquila earthquake it was an ellipse ~26 km by ~13 km, or so), there is the time scale uncertainty. In all cases the only measure that can be taken is the orderly evacuation of the area, in order to save lives and injuries, which of course is of paramount importance. But, this means the need to accommodate thousands to million of people practically for an unknown period of time.

That requires central planning and a need oriented economy which does not exist in most of the countries, but even if it did exist still there is a problem of scientific credibility. From the social point of view someone might argue that it does not matter if the city is evacuated and the earthquake does not occur. It will be a good exercise. But, what about the economic cost because of the evacuation if the earthquake does not occur, and the economic cost of the destruction which will happen anyway, if the earthquake occurs during the time of the evacuation? Much worse what about if the earthquake happens after the return of the population? Or, if you were unsuccessful couple of times who is going to believe you the third time that might be proved to be successful? Then if someone is doing this warning frequently there is a chance, sometime to be successful. But then is it not like gambling? It is obvious that all that adds to discrediting a possibly very legitimate scientific effort.

This is why my opinion is that no matter how much frustrating and oppressing for a scientist might be, and I know it is, the socially responsible position is first to understand the scientific problem by asking the right questions in order to get the right answers, and then if he/she thinks has the right answers act in cooperation with the proper agencies and authorities in order to take the proper actions. In all cases a scientist must unite his/her voice with the people for good structures, constructed with the basic principle they do not collapse in the case of a local strong earthquake, and demand earthquake preparedness in general.

I hope it is understood that I do not undermine any effort. On the contrary I am trying to protect it from an unwarranted discredit, or accusations for a gambling success.

Stavros Tassos

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