Quake Jolts Area North of Tokyo
Date: 31-Dec-04
Country: JAPAN
It said no tsunami warning was issued for the quake, which was centred in the ocean off northern Miyagi Prefecture, 80 km (50 miles) below the seabed.
There were no immediate reports of injuries or damage from the quake, which occurred around 10:29 p.m. (1329 GMT), Kyodo news agency reported.
The magnitude of the earthquake was measured according to a technique similar to the Richter scale, but adjusted for Japan's geological characteristics. The US Geological Survey (USGS) Web site also gave a magnitude 5 reading for the quake.
Earthquakes are common in Japan, one of the world's most seismically active areas. The country accounts for about 20 percent of the world's earthquakes of magnitude 6 or greater.
In October 2004, an earthquake with a magnitude of 6.8 struck the Niigata region in northern Japan, killing 40 people and injuring more than 3,000. That was the deadliest tremor since a 7.2 magnitude quake killed more than 6,400 people in the western city of Kobe in 1995.