Scientists look at Japanese quakes

TOKYO, Nov. 25 (UPI) -- Earthquakes like the one that devastated Japan in March occur about once in every 600 years off the country's east coast, Japanese scientists say.

The Earthquake Research Committee examined evidence of tsunamis over the past 2,500 years, The Yomiuri Shimbun reported. They found the earthquake-caused waves have been more frequent than previously believed.

The last quake of about the same order of magnitude as the Great East Japan Earthquake was believed to be the Jogan Earthquake in 869, more than 1,000 years ago. Some experts used that history to estimate the frequency as about one in a millennium.

The March quake was actually several earthquakes and was followed by a tsunami. The scientists said there have been similar events around the fourth or third century B.C., the fourth or fifth century A.D., the Jogan quake in 869, in the 15th century and this past March.