22 Novembre 2012
November 22, 2012
Expert says maximum M10 earthquake possible
A Japanese seismologist says the maximum scale of an earthquake occurring anywhere in the world would be around magnitude 10, judging from Earth's size and the lengths of quake-triggering faults.
Tohoku University Professor Toru Matsuzawa made the report at a meeting in Tokyo on Wednesday.
A magnitude-10 quake would be 32 times more powerful than the 9.0 earthquake that hit northeastern Japan in March last year. The magnitude-9.5 quake recorded off Chile in 1960 is the world's largest known earthquake to date.
A magnitude-10 quake would occur, for example, if an 8,800-kilometer fault along a northern Pacific Rim trench shifts 20 meters.
Matsuzawa says such an earthquake would result in tremors lasting 20 minutes to one hour, and trigger days of tsunamis.
Matsuzawa stresses he's not saying a magnitude-10 quake would definitely occur. But he notes that Japan was hit by a magnitude-9 earthquake when it had been expecting a maximum magnitude-8, so people should be aware of what could happen.