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Stavros Tassos On L'Aquila Earthquake
Dear Brian
I show your post about the synthetic apperture radar interferogram in L'Aquila earthquake where you state: "I'm pretty sure this data shows the Earth growing. However they only provide two numbers (2.8 centimeters and 25 centimeters) and no vectors. Movement, but to where? It would be interesting if they told us what the interferogram data shows:"
Well, if you look carefully in the Science Daily post, which reads: "Each fringe of the interferogram, corresponding to a colour cycle, is equivalent to an Earth surface displacement of 2.8 cm along the satellite direction (the bold letters is by S.T.)." it is clear that this is vertical movement, i.e., uplift.
Now, since there are ~9 fringes, and each fringe represents 2.8 cm along the satellite direction, the total displacement-uplift at the center of a ~26 km by ~13 km dome is ~25 cm, which corresponds to a volume of ~3.3x10^7 m^3 or ~10^11 kg of Excess Mass. So here is your measured earth growth; and this is not theory. It is hard-core modern technology data.
This earthquake or volcano related doming-uplift, the size of which depends on the earthquake magnitude or volcano size, has been observed before, e.g., Izmit earthquake and Mount St Helens volcano.
As for the prediction of the L'Aquila earthquake be a bit cautious. The problem of earthquake prediction is not solved yet. Especially mainsteamers with their plate tectonics, elastic rebound, and static stress myths have a real problem understanding the physics of the earthquake source. This is why it is almost unanimously recognized that the physics of the earthquake source is not known. It follows that it is impossible to deterministically predict a phenomenon when you do not know the cause and effect relationships that govern the phenomenon itself.
Although there are various precursors, among which the increase in radon content, since an earthquake is a quantized phenomenon you never now if and when the necessary quantum-limit will be reached. It might never be reached or it might be reached within seconds. Then even if we have a swarm of small earthquakes, like in L'Aquila, in the 99% of the cases this is not followed by a much stronger earthquake. The real problem with L'Aquila and other earthquake hit areas is the quality of structures, and earthquake preparedness in general, and of course the reasons if they are not good.
Best regards
Stavros
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4 comments:
Dr. Stavros,
I believe that strong earthquake can be predicted. Radon, helium and methane increasing are good precursors. Also monitoring activity of mud volcanoes if they exist in seimogenic areas. I think that Dr. Thomas Gold theory about possible causes of earthquakes is plausible and can help us save lives if we observe and apply suitable instruments. Dr. Gioacchino Giampaolo Giuliani from Gran Sasso Laboratory in Italy, certainly study a lot and believe that radon emission is suitable to predict earthquakes.
Geologist
Geologist,
Stavros is his first name so it's Dr. Tassos...=)
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 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 (the odd 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., an 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
Thanks by the response.
I think that's more important know about real causes of earthquake better than their consequences. Seismic energy release surely is related to consequences. Try understand chemistry of earthquakes (gas upwelling) together physical phenomena that occur within the earth interior and technology for monitoring lead us to good predictions. Unfortunately many seismologists try to correlate earthquake phenomenon exclusively as "cause" of the plate movements, either within them or far from their boundaries.
Our planet is alive and we need understand it; deducting as you said with the right questions to obtain correct answers.
Geologist
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