CRESCENT CITY, Calif. -- It doesn't matter if the earth sways in Chile, Alaska or Japan, the formation of the sea floor along the U.S. 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 2011, when a Japanese earthquake sparked a tsunami that sank 11 boats, damaged 47 others and destroyed two-thirds of the harbour's docks.
Port officials are hoping that tsunami is among the last of many that have forced major repairs in Crescent City, a tiny commercial fishing village on California's rugged northern coast. Officials are spending $54 million to build the West Coast's first harbour able to withstand the kind of tsunami expected to hit once every 50 years -- the same kind that hit in 2011, when the highest surge in the boat basin measured2.5 metres and currents were estimated at 6.7 metres per second.
Officials are building 244 new steel pilings that will be 76 centimetres in diameter and 21 metres long. Nine metres or more will be sunk into bedrock.
The dock nearest the entrance will be five metres long and 2.4 metres deep to dampen waves. The pilings will extend 5.5 metres above the water so surges 7 will not rip docks loose.
Crescent City was not the only West Coast port slammed by the tsunami, which was generated by a magnitude-9.0 earthquake in Japan. The waves ripped apart docks and sank boats in Santa Cruz, Calif., and did similar damage in Brookings, Ore., just north of Crescent City. But their geographical location doesn't make them as vulnerable to multiple tsunamis.
"Normally, Crescent City takes the hit for all of us," said Brookings harbourmaster Ted Fitzgerald.
Since a tidal gauge was installed in the boat basin in 1934, this small port has been hit by 34 tsunamis, large and small. It typically suffers the most damage and the highest waves on the West Coast, said Lori Dengler, professor of geology at Humboldt State University.
The sea floor funnels surges into the mouth of Crescent City's harbour and the harbour's configuration magnifies them, experts say.
A wave generated by an earthquake in Alaska on Good Friday, 1964, killed 11 people and wiped out 29 city blocks. That was 10 years before the boat basin was even built.
-- The Associated Press