Update: Earthquake Shakes Northeast

An earthquake shook homes and offices throughout much of the northeast on Tuesday afternoon.

The 5.8-magnitude quake, which started shortly before 2 p.m. about 50 miles northwest of Richmond, Va., according to the United States Geological Survey, caused tremors that lasted about seven seconds in Scotch Plains, Fanwood and neighboring towns. Previously, the USGS reported that the event measured a magnitude of 5.9.

Scotch Plains and Fanwood residents did not report any injuries or damage, and no buildings were formally evacuated, police and government officials said. In Newark, Hoboken and other nearby cities, some multi-story buildings were evacuated after they reportedly swayed from the tremors, and Six Flags in Jackson was shut down.

Twelve nuclear power plants in the mid-Atlantic region, including three New Jersey plants in Salem, Hope Creek and Oyster Creek, declared "unusual events," the lowest of four emergency levels. A 13th plant in Maryland declared an "alert," the second-lowest emergency level, after it lost power, but officials there stated that it is receiving electricity from an onsite diesel generator. .

The distance the earthquake traveled remains unclear, but residents and office workers in cities such has New York City, Philadelphia and Washington, D.C., reported feeling the ground shake.

Locally, the tremors were mild. "A lot of people didn't really seem to notice," Scotch Plains Public Library librarian Lynn Favreau said. "I heard the roof creak. It sounded like an animal running across the ceiling."

Fanwood resident Sherry Atta, eating ice cream at on Martine Avenue with her 10-year-old son and his friend, said, "I thought it was just a truck rolling by." 

Many residents missed the earthquake altogether. "I was going into , I had no idea it happened," Scotch Plains resident Jenn Ciampa said. She learned of the earthquake from her husband, who sent a text message to make sure she was OK. "Am I disappointed? A little bit."

New Jersey ranks low on the list of states at risk for experiencing an earthquake, according to the Federal Emergency Management Association.

"Earthquake hazards are measured as the likelihood of experiencing earthquake shaking of various intensities," FEMA's website states. Northern New Jersey is put in a category that's described as "having a hazard shaking of moderate intensity," which could be felt by all and could lead to slight damage.

Southern New Jersey is put in a category described as having "a small probability of experiencing damaging earth quake effects."