Tsunami grazes US West Coast, thousands evacuate

Thousands of people fled their homes along the California coast as a tsunami triggered by the massive earthquake in Japan began hitting the US West Coast after rolling through Hawaii.

But the giant wall of water appeared to have lost much of its energy as it roared thousands of miles (km) across the Pacific Ocean toward North America, according to initial reports from officials in the United States, Mexico and Canada.

The tsunami was expected to reach South America's coastline later.

Tidal surges in the Hawaiian island chain were not much higher than normal, officials there said. There were no reports of injuries or severe inland property damage and the tsunami warning was later downgraded to an advisory.

"The models are showing that the waves are dying down and so hopefully this event will be over in two to five hours," Laura Furgione, a senior official at the US National Oceanic and Atmospheric Administration, told reporters.

Waves crashing ashore along the Californian coast were larger than normal, but only the town of Crescent City, near the California border with Oregon, and Santa Cruz, 72 miles (115 km) south of San Francisco, appeared to suffer any real damage.

About 35 boats and most of the harbor docks were damaged in Crescent City, where waves were more than 6 feet (2 metres), while Santa Cruz sustained about $2 million in damages to docks and vessels, emergency management officials said. Four people in Crescent City were swept out to sea but later rescued, officials said.

Thousands of residents were evacuated along the California coast, including 6,000 near Santa Cruz, said Jordan Scott, spokesman for the California Emergency Management Agency.

In Hawaii, 3,800 miles (6,200 km) from Japan, the main airports on at least three of the major islands -- Maui, Kauai and the Big Island of Hawaii -- were shut down as a precaution, and the US Navy ordered all warships in Pearl Harbor to remain in port to support rescue missions as needed.

Civil defense sirens blared statewide, starting shortly before 10 pm local time, and police with bullhorns urged residents near shore to higher ground.

No injuries or property damage were reported after a series of four tsunami waves hit the Hawaiian island of Oahu, said John Cummings, a spokesman for emergency management in Honolulu. The tsunami warning for Hawaii was later downgraded to an advisory.

President Barack Obama, a native of Hawaii, was notified of the massive Japanese quake at 4 am/0900 GMT and instructed the Federal Emergency Management Agency to be prepared to help affected US states and territories, the White House said.