Hi Ara. The area that the Japanese are concerned with the most is the Tokai region. This is along the Nankai trough just off the Pacific coast. Japan has very good records and there are no records showing a rupture similar to Sumatra has occurred in, but the possibility can’t be ruled out. Two other regions that could go at the same time are Tonankai and Nankai.

The expected earthquake will most likely generate a tsunami that will strike the coast in about 2 minutes.

The Tokai segment last ruptured in 1854, and before that in 1707. Both events were great earthquakes of magnitude 8.4. The segment ruptured in comparable events in 1605 and in 1498. The pattern is pretty stark: a Tokai earthquake has happened about every 110 years, plus or minus 33 years. As of 2005, it has been 151 years and counting.

The maximum death toll in a tsunami from a Tokai temblor is estimated at 2,200. The number is expected to reach 8,600 if quakes hit the Tonankai and Nankai regions at the same time.

Experts have long warned that the areas near the Nankai trough, which stretches off the coast of Tokai through the Shikoku regions, are danger zones that have historically witnessed a lot of earthquake activity.

An example is the Tonankai Earthquake off the eastern coast of the Kii Peninsula in 1944. More than 900 people died in the disaster.

Two years later the Nankai Earthquake struck south of the peninsula and killed at least 1,300.

A Nankai trough temblor at the close of the 15th century is believed to have killed 40,000 people. Take Care…Don in creepy town

http://www.eri.u-tokyo.ac.jp/seno/Papers/eps.tokai.fbm.pdf

http://www.terrapub.co.jp/journals/EPS/pdf/5103/51030147.pdf

http://www.pmel.noaa.gov/its2001/Separate_Papers/1-08_Kawata.pdf

http://www.quakes.uq.edu.au/ACES/ACES-2002-workshop/PDF/page295-300.pdf