A major earthquake has struck off the coast of northern California, briefly prompting a tsunami warning along the US Pacific coast.

There were no immediate reports of damage or injuries.

The magnitude 7 quake struck at about 7.50pm (2350 GMT) on Tuesday, southwest of the coastal community of Crescent City and 480km northwest of San Francisco, according to the US Geological Survey.

Witnesses felt buildings shaking along the California coast but there were no immediate reports of damage.

A tsunami warning was briefly sounded from the California-Mexico border north to Vancouver Island, in Canada, but was called off about an hour after the quake hit.

The area hit is where the North American, Pacific Ocean and Juan de Fuca plates converge and has earthquakes of this magnitude about once a decade, said Lucy Jones, the scientist in charge of the US Geological Survey office in Pasadena.

Crescent City is the site of the only known tsunami to cause deaths in the continental United States.

Eleven people died and 29 city blocks were washed away when a tsunami spawned by a quake hit the coastal community in 1964.

PHOTO CAPTION

Seismograph image. (AFP)