California town builds 'tsunami-resistant' port

It does not matter if the earth sways in Chile, Alaska or Japan, the formation of the sea floor along the US west coast generally aims any tsunami surges at the tiny California port town of Crescent City.

Churning water rushes into the boat basin and then rushes out, lifting docks off their pilings, tearing boats loose and leaving the city's main economic engine looking as if it has been bombed.

That's what happened in March last year, when a Japanese earthquake sparked a tsunami that tore across the Pacific before reaching Crescent City, where it sank 11 boats, damaged 47 others and destroyed two-thirds of the harbour's docks.

Port officials are hoping that tsunami will turn out to be the last to cause such havoc for the tiny commercial fishing village on California's rugged northern coast. Officials are spending US$54 million to build the US west coast's first harbour able to withstand the kind of tsunami expected to hit once every 50 years - the same kind that hit last year, when the highest surge in the boat basin measured 2.5 metres and currents were estimated at 6.7 metres per second.

Officials are building 244 new steel pilings that will be 75cm in diameter and 21 metres long. They will be sunk nine metres deep into bedrock. The pilings will extend 5.5 metres above the water so that surges 2.3 metres up and down will not rip docks loose. Crescent City was not the only west coast port slammed by the tsunami, which was generated by a magnitude-9 earthquake in Japan.

The waves ripped apart docks and sank boats in Santa Cruz, California, and did similar damage in Brookings, Oregon, just north of Crescent City. But their geographical location doesn't make them as vulnerable to multiple tsunami.

"Normally, Crescent City takes the hit for all of us," said Brookings harbour master Ted Fitzgerald.