Via The LA Times:
A 3.6-magnitude earthquake struck near the Gaithersburg, Maryland, area just after 5 a.m. ET Friday, according to the U.S. Geological Survey.
The center of the quake was about 20 miles northwest of Washington, the USGS said.
The earthquake was the largest in the area since 1974 — and the first registering above 3.0 on the Richter scale there in that time period, said Amy Vaughan, a geophysicist at the USGS National Earthquake Information Center. “This is a significant event for the region,” she said.
About an hour after the quake, Vaughan said more than 5,500 people had reported feeling it across Maryland, in nearby Washington, and in states including West Virginia, Virginia, Delaware.
“It was really loud, like a plane flying really low. I had never felt anything like it,” said Anne Ngunjiri, 30, of Gaithersburg. “I was jolted out of bed. All my neighbors woke up. After it passed, I thought it could be an earthquake, and lay in bed hoping there were no aftershocks.”
Judy Rudolph, 64, said she was writing e-mails in bed in Rockville, Maryland, when her house started to shake.
“My first reaction was the noise . I thought it was an explosion,” she said. She said she’d never felt anything like it in her 31 years living there. Until Friday, the largest earthquake recorded within a 75-kilometer (about 47 miles) radius of Gaithersberg since 1974 was a 2.7-magnitude quake in 1993, Vaughan said. The last earthquake in Maryland occurred on October 8, 2007, according to the USGS website. It was a 1.7-magnitude quake about 5 miles northwest of Baltimore.