Vincent Courtillot a donné une conférence, intitulée "Le méga séisme et le tsunami du 11 mars 2011 au Japon", à l'occasion du 59ème Congrès national des professeurs de physique et de chimie (Udppc) qui s'est tenu le 26 octobre dernier à l'Université Montpellier 2.
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Dear Prof. Courtillot,
RépondreSupprimerif my knowledge of the French language was sufficient to understand your lecture correctly, one is actually able to recognize the situation when the movement of plates stalls -- simply by measuring the distance between the plates in a given region and by observing a deceleration or even halt in their relative motion. I understood that this would mean that the plates are now jammed and also that an earthquake would become more and more probable along with the rising mechanical tension.
Now I'm asking myself if it could soon become feasible to control the instant of time when the quake will happen, i.e., to trigger it on purpose.
Some time ago, I read a geologic dissertation which designed a system to deposit waste by making use of the property of certain rocks to become pasty when put under heat and pressure. The author proposed to drill a mine shaft, small in diameter, but about a kilometer deep for stacking specially constructed, barrel-shaped containers therein. These containers would have to be loaded with the right balance of highly active and other nuclear waste to achieve a temperature and pressure such that the rock formation below just begins to flow. In effect, the whole column would sink in and would finally be sealed within a hull (a cocon) of again solidified rock.
Now I haven't any idea how fast such a column would proceed in sedimentary and basaltic rocks when trying to reach a depth of, say, 30 kilometers. But if you are in a the situation where you can predict a quake to occur within 30 years, such a stack would probably still have the time to proceed for some years (with mean speeds well below 1 mm/s). Anyway, the general idea is to use a self-dislocating device to trigger a probably much weaker quake upon reaching the boundary layer between the overlapping plates.
I realize that there are plenty of problems related to the domain of materials science, and also legal questions related to damage compensation (similar to the situation when authorities would decide to artificially trigger a snowslide, which then happens to bury a nearby village. Would the village had suffered the same damage pattern without the intervention?)
Another problem which I can't quantify is the amount of energy that would be needed to trigger a quake artificially. Perhaps not so much towards the end of the phase preceding an imminent quake?