Last count on the earthquake that happened in Japan yesterday, is a slab of the Earth is cracked, not as large as expected.
A cracked slab region of the earth was small, with a length between 300 and 400 kilometers. In comparison, the magnitude 9.1 earthquake that occurred in Aceh (Indonesia) in 2004 produced 1,300 km along the slab cracks. Similarly, as quoted by New Scientist, Saturday (March 12, 2011).
Then, why the quake was very strong? It happens when two tectonic plates shifted along the 40 meters. This calculation is obtained Chen Ji of the University of California, Santa Cruz.
To be able to produce these calculations, Chen Ji download information about seismic waves are present at stations around the world, and then reversing the data, to see the cracks resulting from the seismic energy.
Calculations of Chen Ji stated that cracks along 400 km of the slabs there is an area of 40 meters. Meanwhile, the U.S. Geological Survey estimate a wide cracks are only 20 meters
It seems this is one slab of Earth's movement in the world and have a huge impact in the future earthquake in the region, as pressure during an earthquake can be referred to the nearest crack.
"This earthquake increases the pressure conditions and the potential for cracks to broken in the south and north. It could take several months or years," said Chen Ji.
Once the conditions in Japan have recovered, then this data will provide a detailed information on how the quake could cause a major tsunami.