Japan Tsunami Warning Downgraded

Thousands of residents fled to higher ground after an 8.3 magnitude earthquake struck off Japan's northern coast in the Pacific on Saturday, setting off tsunami warnings.

Japan's Meteorological Agency later downgraded its tsunami warnings to advisories for the highest risk areas, prompting some municipalities to lift evacuation orders.

A tsunami warning also was issued for Alaska's western Aleutian islands, prompting some residents to evacuate, and a tsunami watch was issued for Hawaii. Both were later canceled.

The Japanese meteorological agency had said that waves as high as 3.3 feet could hit the northeastern coast of Japan's main island of Hokkaido.

But the largest wave reported was a 16-inch tidal swell that twice hit the shores of Chichi-jima, a Pacific island 620 miles south of Tokyo, more than three hours after the quake.

Earlier, a tidal swell of about 4 inches was recorded in the northeastern coastal town of Nemuro about an hour after the quake, and small swells in the tide also were observed in other coastal towns, including Kushiro, Abashiri and Otaru, the agency said.

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

"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 ones come in bigger waves."

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

The quake struck around 1:24 p.m. about 310 miles east of Etorofu, 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 8.3 magnitude quake struck 19 miles below the seabed, the agency said.

The U.S. Geological Survey registered the earthquake with a magnitude of 8.2.

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

Meanwhile, residents of two remote islands evacuated Friday night after officials issued a tsunami warning for Alaska's western Aleutian islands that was later canceled after waves recorded by tidal sensors proved to be small.

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

The Japanese 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 7.8 inches.

Seismologists, however, warned that this time the 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. "I urge everyone to stay alert," he said.

On Dec. 26, 2004, a magnitude-9.0 earthquake off Indonesia's Sumatra island spawned giant waves that fanned out across the Indian Ocean at jetliner speeds, leaving at least 230,000 dead and millions of homeless in its wake.