Roots of Fukushima: Japanese drill epicenter

Drilling research vessel "Chikyu» (Chikyu) Identify causes of earthquakes off the coast of Japan on March 11, 2011, which caused a tsunami, the catastrophic destruction and has killed more than 23,000 people. Its mission — to drill the earth's crust in the fault zone near the epicenter of the earthquake.

Black point — the epicenter of the earthquake, the red — the place of the planned drilling For decades, scientists are trying to determine the role of friction between tectonic plates in earthquakes. One of the research — the nature of the tsunami. It remains unclear why some earthquakes cause tsunamis, while others, such as strong — no.The proposal to use the vessel "Chikyu", built specifically for ultra-deep drilling program of oceanic crust, was announced shortly after the earthquake. But the management of the program approved it only now, and to work the ship can proceed only in April next year. However, scientists believe that drilling will take place "without delay" with the speed of the processes occurring in the Earth's crust. This will be the first time that researchers can explore depths of the earth in the epicenter soon after it happened.

Drilling vessel "Chikyu"

The scientific study of the project, called "Project Fast drilling in the Japan Trench» (Japan Trench Fast Drilling Project), based on a report by seismologists, the earthquake of 2009, in which the tectonic plates shifted by about one meter. Earthquake on March 11 set the record for the distance at which simultaneously moved plate: about 50 meters.

This makes it an ideal target fault zone drilling. "The fundamental problem of seismology — figuring out how the stone can move in the depths of tens of meters", — says James Mori, a seismologist at Kyoto University. Researchers believe that the earthquake because of crushing stone or high water pressure is greatly reduced resistance between arrays of stone, sand and water in the fault zone. But to study this effect has not yet succeeded.

Since friction has the effect in the form of heat dissipation, temperature at depth will give scientists more accurate data upon which to form a theory. Previous attempts to drill in the fault zone after other earthquakes showed a slight increase in temperature, or not show it at all. But the big shift in this case gives a better chance of detecting the residual thermal effects.

Boer "Chikyu" to deepen the rift in 1 km, after which the well will lower sensors. The project involves monitoring temperature over from one year to three years, depending on the results. It is the longest period of monitoring of all attempts, and it will calculate the total amount of heat released by the earthquake. As a result, it will be possible to determine the friction between the plates in place of the fault, to fill a gap in the model of the earthquake, and perhaps to understand its cause.

Source: planeta.moy.su.

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