A magnitude-5.1 earthquake struck off the Humboldt County coast at 6:52 p.m. Friday with a quick jolt but no damage. At 11:04 p.m., another jolt, this time a magnitude 5.3 quake, shook the North Coast.
The first quake, located 70 miles west of Ferndale at a depth of 6.2 miles, was felt from Fort Bragg to Arcata, according to U.S. Geological Survey website responses.
The second quake, located 52 miles west of Ferndale, also shook from Fort Bragg to Arcata.
The Humboldt County Sheriff’s Office and Eureka Police Department received no reports of damage or injuries, according to dispatchers.
Humboldt State University professor Mark Hemphill-Haley said the earthquake likely occurred on the Mendocino Fault, which runs east-west off Cape Mendocino. The fault is capable of producing earthquakes up to magnitude 7. Friday’s earthquake was not big enough to produce a tsunami, Hemphill-Haley said.
The earthquake was likely a strike-slip earthquake, in which two sides of the fault are moving horizontally, Hemphill-Haley said.
He also added that the shallowness of the quake is not surprising. “Most earthquakes that occur well offshore are going to be pretty shallow,” Hemphill-Haley said. “You’re not going to get a whole lot of people to feel it.”
John Myers, a senior clerk at the North Coast Co-op in Eureka, said he didn’t feel the earthquake.
”Nobody said a word,” he said, adding that none of the customers or employees felt the earthquake either. “That is hysterical. The big one almost shook us to pieces, but we didn’t get a thing this time.”