The United States Geological Survey said that the quake hit at the depth of seven miles (11.2 km) at a distance of 35 miles (56 km) west-northwest of Petrolia in Carlifornia.
There is was no tsunami warning issued and the police is not expecting to receive any reports of injuries or damage.
"Spilled coffee is about the worst thing," Lt Murl Harpham of the Eureka Police Department is quoted as saying in media reports.
This is the second largest quake to hit the region in a month's time. On Jan 9, a 6.5 magnitude earthquake struck off the coast of Eureka. There was some damage to property reported.