Asahi: Expert says Japan should be prepared for possibility of M10 quake — “Days of tsunamis” — Only 1 magnitude below asteroid strike (VIDEO)
November 23rd, 2012
Researcher: Japan should prepare for worst-case magnitude-10 earthquake
Author: SHIGEKO SEGAWA
Date: November 23, 2012
Japan should be prepared for the possibility of a magnitude-10 earthquake, although the chances of a temblor that size are slim, a seismologist said.
If a temblor of such a scale should strike, the underground rupture would continue for 20 minutes to an hour, meaning tsunami could hit coasts before the shaking subsides.
If a 3,000-kilometer stretch from the Japan Trench to the Kuril-Kamchatka Trench along the Pacific Ring of Fire has a slip of 60 meters, that would constitute a magnitude-10 earthquake, [professor Toru Matsuzawa of Tohoku University] said.
The energy of a magnitude-11 quake, 30 times more powerful than a magnitude-10 temblor, would be equivalent to that of the asteroid impact that is believed to have caused the extinction of the dinosaurs 65.5 million years ago. Such a quake would cause a shift extending more than 20,000 kilometers. Matsuzawa concluded that consideration would not be needed for such an earthquake.