Earthquake off California coast
There were so far no reports of casualties and the tsunami warning was quickly cancelled.
This is the third quake along the Pacific edge of the Americas in less than 48 hours.
One struck northern Chile late on Monday killing 11 people and a second was felt in the Aleutian Islands, off Alaska, on Tuesday.
The earthquake occurred Wednesday at 0250 GMT about 146km (91 miles) west of Crescent City, which was hit by a tsunami in 1964.
The tsunami warning covered the entire western coast of the US before it was cancelled.
Witnesses felt buildings shake along the Californian coast but there were no immediate reports of damage.
Monday's earthquake in northern Chile had a magnitude of 7.9 and was felt in neighbouring Peru and Bolivia.
The Alaskan 6.8 magnitude quake struck in the region of the Rat Islands, part of the Aleutian Islands. There were no reports of casualties or damage.