Surges of 2.4 meters high crashed ashore on the coasts of California and Oregon yesterday, up to 12 hours after the 8.9-magnitude quake triggered tsunami alerts in dozens of countries across the Pacific.

In California's Del Norte County, a 25-year-old man was confirmed dead after being swept into the Pacific Ocean near the mouth of the Klamath River.

The man and two friends were taking photographs of the incoming tsunami waves. "We have at least 35 boats that have been crushed. We have boats on top of other boats," said Cindy Henderson, emergency services manager in Crescent City, 350 miles north of San Francisco.

The US Coast Guard added that there had also been damage to about six boats in a marina in Santa Cruz, further south, after they collided with each other due to the buffeting tsunami waves.

Santa Cruz port director Lisa Ekers estimated the damage at more than USD 10 million, according to CNN.

California's governor Jerry Brown, meanwhile, declared a state of emergency in four of the state's coastal counties -- a procedure that unblocks federal funds to help with the clean-up.

Before reaching the US mainland the tidal waves hit Hawaii, which had been given only four hours to evacuate low-lying areas, sirens blared as locals and tourists scrambled to higher ground.

Many residents had already taken refuge in shelters, after the Pacific Tsunami Warning Centre issued an ocean-wide alert for the giant waves along the West Coast, down through Central and South America as far as Antarctica.

Several hours later, Hawaii Governor Neil Abercrombie said the tsunami warning had been downgraded to a tsunami advisory.

"Although we were fortunate that a more destructive tsunami did not materialise, I can assure everyone that our agencies and officials are well-prepared to respond to emergencies of this nature," the governor said.

Canada also issued an alert for the north coast of British Columbia, warning it may "produce strong currents dangerous to those in or near the water."

The tsunami warning came after the largest ever recorded earthquake in the Asian nation's history, triggering walls of water which swamped the Japanese coastline and left hundreds of people dead.