Powerful quake off Japan's north coast sparks tsunami warning, thousands flee

TOKYO (CP) - A powerful magnitude 8.2 earthquake struck off Japan's northern coast in the Pacific on Saturday, sparking tsunami warnings and sending thousands of residents along the archipelago's eastern coast fleeing to higher ground, officials said. Japan's Meteorological Agency earlier downgraded tsunami warnings on the island to advisories and later cancelled the advisories altogether on the northwestern coast of Hokkaido. Advisories in other parts of Hokkaido and towns facing the Pacific coast were still in effect.

The Hokkaido government lifted evacuation orders to all 85,000 coastal residents in 22 towns as the fear of killer waves subsided, state official Koji Urano said, adding that he also expected the meteorological agency to entirely lift tsunami advisories soon.

Tsunami watches were initially issued for parts of British Columbia and Hawaii. A tsunami warning was also issued on Alaska's western Aleutian islands, prompting some residents to evacuate. All of those warnings and watches were later cancelled.

Department of Fisheries and Oceans spokesman Dennis Sinnot said the waves caused by the earthquake would be virtually indistinguishable when they arrived on B.C. shores.

"Nothing that the naked eye would really see," he said early Saturday morning. "You'd have to really be looking for it."

The quake struck around 1:24 p.m. local time near the Kuril Trench, about 500 kilometres east of the Etorofu island, the largest of a disputed four-island chain known as the Northern Territories in Japan and the Kuril islands in Russia, the agency said.

The largest wave of 40 centimetres twice hit the shores of Chichi-jima, a Pacific island about 1,000 kilometres south of Tokyo, more than three hours after the quake. The island has a population of about 2,000.

Earlier, a tidal swell of about 10 centimetres was recorded in the northeastern coastal town of Nemuro about an hour after the quake. Small tidal swells were also observed in other coastal towns, including Kushiro, Abashiri and Otaru, the agency said.

There were no immediate report of injuries or damage from the quake, Hokkaido state police spokesman Shinji Yamakoshi said.

Yamakoshi said he did not feel the quake in the state police headquarters in Sapporo, western Hokkaido.

The quake struck 30 kilometres below the seabed, the agency said.

The agency also issued weaker tsunami warnings to dozens of cities as far as Wakayama in the western region of Japan's main island of Honshu.

Hokkaido disaster prevention official Haruyuki Komatsu said the island state issued evacuation orders to 85,000 people in 22 coastal towns, and thousands of people had gathered at community centres.

Among them, the town of Abashiri requested a dispatch of defence troops to provide blankets and other relief goods for the evacuees, while local police closed off roads to the coast to keep people away from possible danger. Local train operators suspended some services as a precaution.

"The tidal change so far seems rather small, but a bigger one may come hours later," Komatsu said. "So we have to stay vigilant into the night in case a second or a third one comes in bigger waves."

But Kushiro city lifted the evacuation order to more than 2,000 coastal residents as the agency downgraded its tsunami alert to an advisory, Kyodo News agency reported.

Earlier, Hideo Suzuki, an official of Rausu town on the eastern coast of Hokkaido, said he had not observed any visible change to the sea level, although the town has ordered all residents to evacuate via community broadcasts.

Nemuro official Yasuaki Imai said the city issued tsunami warnings to residents through a disaster alert broadcast system over community speakers as municipal officials patrolled coastal areas to monitor the situation.

Temblors of magnitude 7 are generally classified as major earthquakes, capable of widespread, heavy damage.

The meteorological agency also issued warnings last November following a magnitude 7.9 quake in a similar area, but most areas saw waves of only about 20 centimetres high.

Seismologists, however, warned that Saturday's quake was stronger and cautioned residents to remain vigilant.

Tokyo University seismologist Yoshinobu Tsuji warned that high waves may still hit the region, hours after a tsunami warning.

Citing tidal changes being observed in some locations, Tsuji said "we should assume it's coming . . . I urge everyone to stay alert."

Tsunami waves - generated by earthquakes - are often barely noticeable in the ocean but can rise to great heights once they arrive on shore.

A magnitude 9.1-magnitude earthquake off the coast of Indonesia on Dec. 26, 2004, caused a tsunami that killed more than 230,000 people in 11 countries.

© The Canadian Press, 2007