A 6.5 magnitude earthquake struck Thursday morning off the Northern California Coast in Humboldt County that was felt in the Bay Area, officials said. The quake hit on the Mendocino fault at 6:50 a.m. in the Pacific Ocean, about 100 miles off coast of Ferndale, according to the U.S. Geological Survey. There were no immediate reports of damage and no tsunami warning was issued, said a dispatcher for the Humboldt County Sheriff’s Office. John Bellini, a geophysicist with the USGS in Golden, Colo., said the earthquake was center on the Mendocino fault, 6 miles beneath the ocean floor and about 100 to 110 miles of west of Eureka. Several aftershocks were reported in the same area, including a 5.0 magnitude shaker at 8:32 a.m.