Japanese papers reveal huge quake

http://news.bbc.co.uk/2/hi/science/nature/3247142.stm

Scientists say old Japanese papers show a huge magnitude nine earthquake
struck north-western America 300 years ago.
The writings report damage from a five-metre-high tsunami that washed on to
the Japan coast on 26 January, 1700.

Computer modelling allowed Kenji Satake of the Geological Survey of Japan
and colleagues to model the size and source of the quake that created the
wave.

A magnitude nine event would, in a few minutes, release about as much energy
as the US now consumes in a month.

The simulations show the earthquake probably ruptured the full length of a
fault, known as the Cascadia subduction zone, which extends more than 1,000
kilometres [600 miles] along the Pacific coast from southern British
Columbia to northern California. ...