A powerful magnitude 6.5 earthquake rocked the Northern California coast Thursday morning.
The quake occurred under the Pacific Ocean about 100 miles west of Ferndale, near the Oregon border, about 6:50 a.m., the U.S. Geological Survey said. There were no reports of injuries or damage.
The quake's epicenter was about 6.2 miles deep, according to the USGS. which issued no tsunami warnings in connection with the temblor.
According to USGS mapping, the quake, while strong, did not produce violent shaking on land.
The 6.5 jolt was followed by another quake less than two hours later. A magnitude 5.0 temblor hit at 8:32 a.m. in the same area, about 108 miles offshore.
There were no reports of damage in the communities of Ferndale or nearby Fortuna, Fortuna police Lt. Matthew Eberhardt told The Times.
"The radio is quiet," he said.
Eberhardt said he felt the quake while getting ready for his shift Thursday morning.
"It kind of felt [more] like a rolling than a jerking," he said.
Other cities along the coast also reported the shaking.
"Nice shaker," Eureka Police Chief Andrew Mills said on Twitter. "No damage reports, no #tsunami."
The first quake was felt from southern Oregon south into the San Francisco Bay Area. It was also felt inland in the Sacramento Valley, the USGS said.
By 8 a.m., nearly 2,000 people reported feeling the quake with light shaking, according to the USGS "Did You Feel It? map.
Soon after the quake, Bay Area residents took to social media to report the shaking. Some residents said they were rattled from their sleep.
Bay Area Rapid Transit trains ran 10 minutes slower and at reduced speeds in San Francisco because of "seismic activity."
California's north coast is one of the state's most seismically active areas, regularly producing major earthquakes. There had been other smaller quakes in the area in recent days.
In January 2010, a 6.5 quake hit the area, snapping power lines, toppling chimneys, knocking down traffic signals, shattering windows and prompting the evacuation of at least one apartment building.
A 6.9 earthquake that struck in the same area in 2014, but like Thursday's temblor centered miles off the coast, did little damage.
The north coast sits along the Mendocino Triple Junction, where the Pacific, North American and Juan de Fuca tectonic plates collide.
Seismologist Lucy Jones said the earthquake early Thursday was on the Pacific-Gorda plate on the end of the San Andreas Fault.
Generally, seismologists say, a major quake like this will be followed by numerous smaller aftershocks.
Perhaps local dairyman Dennis Leonardi summed up the quake best in an interview with the Ferndale Enterprise.
"The cows were dancing to the rock 'n' roll."
1:55 p.m.: This article was updated with reaction from Eureka Police Chief Andrew Mills.
12:55 p.m.: This article was updated with additional reaction.
9:10 a.m.: This article was updated with additional details about a smaller quake.
8:10 a.m.: This story was updated with details on shaking and a comment from Lucy Jones.
7:45 a.m.: This article was updated with a witness account and background.