Japan braces for 10-foot-high tsunami after 7.6 earthquake

A powerful 7.5-magnitude earthquake shook northeastern Japan late on Monday, prompting orders for about 90,000 residents to evacuate and tsunami warnings that hours later were downgraded to advisories.

The Japan Meteorological Agency (JMA) said a tsunami as high as three metres (10 feet) could hit Japan's northeastern coast after the earthquake struck at 11:15 p.m. (1415 GMT).

Tsunami warnings were issued for the prefectures of Hokkaido, Aomori and Iwate, and tsunamis from 20 to 50 cm (7 to 18 inches) high were observed at several ports, JMA said.

The epicentre of the quake was 80 km (50 miles) off the coast of Aomori prefecture, at a depth of 50 km (30 miles), the agency added.

On Japan's 1-7 scale of seismic intensity, the tremor registered as an "upper 6" in Aomori prefecture -- a quake strong enough to make it impossible to keep standing or move without crawling. 

In such tremors, most heavy furniture can collapse and wall tiles and windowpanes are damaged in many buildings.

The United States Geological Survey said a magnitude 7.6 earthquake struck Japan on December 8, with its epicenter about 70 km off the coast of Aomori prefecture.

East Japan Railway (9020.T) suspended some services in the area, which was also hit by the massive 9.0-magnitude quake in March 2011.

No irregularities were reported at nuclear power plants in the region run by Tohoku Electric Power (9506.T), and Hokkaido Electric Power (9509.T), the utilities said. Tohoku Electric did say, however, that thousands were without power.