A 6.5-magnitude earthquake shook the Pacific Ocean floor about 100 miles off the Northern California coast Thursday morning, causing some light shaking along coastal communities in the state, according to the U.S. Geological Survey.
The quake, centered about 102 miles west of Ferndale and 279 west northwest of Sacramento, struck around 6:50 a.m. PT. at a depth of about 7.5 miles.
USGS initially said the magnitude was 6.8, but later revised it.
Light shaking was reported from east central Oregon to areas a few dozen miles south of San Francisco, USGS reported.
The quake was followed by a magnitude-4.7 temblor that hit just after 8:30 a.m., according to USGS.
No tsunami threat is expected from the initial earthquake, according to the Pacific Tsunami Warning Center.
There have been no immediate reports of injuries or major damage.
The seismic activity led to inconveniences for some commuters in the San Francisco Bay Area, as BART trains temporarily moved at a reduced speed in the aftermath of the temblor, which led to delays of about 10 minutes.
The move was described as a precautionary measure, CNN affiliate KGO in San Francisco reported.
According to seismologist Lucy Jones, the earthquake struck at the Pacific-Gorda pate boundary, at the north end of the San Andreas Fault.
The earthquake “means nothing for SoCal,” Jones tweeted in response to a question about any possible ramifications for the southern part of the state.
California’s north coast, among the most seismically active areas in the region, had experience smaller temblors in the days preceding the magnitude-6.5 one, the Los Angeles Times reported.
The offshore area off of Northern California has experienced some larger quakes in the past two years, including a magnitude-6.9 temblor in March 2014, and two earthquakes with magnitudes above 5.0 that struck weeks apart in January 2015.