The country's Prime Minister's office reports that at least six people have been killed and several are missing as "10-metre-high waves continue to crash [on] coastal villages".

Reports from police at Gizo - the capital of the western province and a popular destination for divers - said water now completely covered the lower areas of the town, while waves continued to pound the nearby towns of Noro and Munda.

About 50 homes in Gizo - just 45 kilometres from the centre of the quake - had reportedly been flattened and boats had been washed into the town.

There were reports that large waves had penetrated 500 metres inland, wiping out villages.

Thousands of people living along northern Japan’s Pacific coast fled to higher ground Wednesday after a powerful undersea earthquake prompted tsunami warnings as far away as Alaska. Waves generated by the quake hit Hawaii hours later without causing problems, officials said.

The 8.1-magnitude quake struck an area claimed by both Russia and Japan, but the waves near Japan did not swell higher than 23 inches. There were no immediate reports of casualties or damage.

Six hours later, tsunami waves up to nearly 4-feet high caused by the quake crashed into Hawaii’s shores, civil defense officials said.

In Crescent City -- about 20 miles south of Oregon's state line -- harbor workers noticed a fast-moving current around mid-afternoon that harbor master Richard Young described as a "river within the ocean."

As the surge rushed out of the harbor, workers noticed that two floating docks in the inner basin were destroyed, Young said. Another surge followed, severely damaging a third dock, he said. The harbor can accommodate up to 200 boats up to 75 feet long.

No injuries were reported, and the surge did not sink any boats. But several vessels attached to the destroyed docks bobbed away from their anchorage and likely received dings and possibly greater damages, the harbor master said.

Young said the replacement costs of the docks could range from $300,000 to $700,000.

Two ice surges, known to Alaska Natives as ivus, stunned residents who had never seen such large blocks of ice rammed ashore.

"It just looked like a big old mountain of ice,'' said L.A. Leavitt, 19, who left his nightshift job at the city to check out the ridges.

Ivus are like frozen tsunamis and crash ashore violently. They have killed hunters and are among the Arctic's most feared natural phenomena.

The ivus crashed ashore Tuesday after strong winds from Russia and eastward currents began pushing pack ice toward Barrow last weekend, said North Slope Borough disaster coordinator Rob Elkins.

By late Monday, thick, old sea ice known as multiyear ice had shoved younger, thinner ice onto shore.

Tens of thousands of survivors are still living in tents and it is estimated that at least 80,000 new houses need to be built.

"I would like to ask the president for a house because right now it's in a bad condition," Marriatti, 39, told Reuters news agency. "I had to build a house by myself."

Sri Lanka has been paying tribute to more than 30,000 people who were killed on the island.

Around the island, small private ceremonies were held to mark the moment the waves struck.

Sweden, which lost 543 people, was the country outside Asia which suffered the most in the tsunami, closely followed by Germany. They were among the foreign tourists included in the 230,000 people around the Indian Ocean who died.

"The unthinkable happened and nothing can undo it," said Martin Jamtlid, leading a minute's silence in front of hundreds of relatives and others at a memorial ceremony in the Skansen park. King Carl XVI Gustaf and his family also attended.

"The year that has gone by has been the longest in my life, at the same time it all seems like yesterday," added Jamtlid, who lost nine family members, his voice shaking with grief.

Casualties. As the 2004 Sumatran tsunami amply demonstrated, a large tsunami poses a major risk to human life, primarily from flooding and debris impact. Evacuation is possible and can save many lives if carried out properly. However, a poorly coordinated evacuation can actually put people in harm’s way. Moreover, the short time frame between event and tsunami for local events requires that the local population be aware enough of the appropriate action to evacuate without official notification. Of the five Pacific states, California has the largest population exposed to tsunami risk. NOAA has estimated that more than one million people in California live within coastal areas vulnerable to tsunami inundation (the rushing in of the water causing flooding and battering by debris). That number does not include one million or more visitors to California's beaches on any given summer day.

Along with threatening lives and property, a giant tsunami would strike an economic blow to the state, given the vulnerability of its ports, the report said.

If a tsunami shut down the ports of Los Angeles and Long Beach for two months, the economic loss could reach $60 billion. The ports make up the third busiest port in the world, but its docks and terminals are only about nine feet above the water. A separate report issued March concluded a Southern California tsunami could cost at least $42 billion.

A massive wave higher than that could cause extensive damage, the report said. Thousands of pleasure boats and other crafts could come loose, and vehicles, equipment, containers and tools could get washed away.

1. Total Destruction of Earth
2. Gulf Coast Tsunami
3. East Coast Tsunami
4. Heat Waves
5. Midwest Earthquake
6. Supervolcano
7. Los Angeles Tsunami
8. Asteroid Impact
9. New York Hurricane
10. Pacific Northwest Megathrust Earthquake

Nearly six months after the disaster that killed more than 31,000 people in Sri Lanka, studies have found that the tsunami waves have pushed seeds of so-called alien invasive species from their coasts farther inland on the tropical island, the United Nations Environment Program said.

"In some areas, including important national parks, the wave has encouraged the spread of alien invasive species, such as prickly pears and salt-tolerant mesquite," the agency said in a statement.