Did you feel it?

It was the question being asked by residents across the Northeast on Friday morning following what the U.S. Geological Survey says was a rare 4.8 magnitude earthquake centered near Whitehouse Station, N.J.

The USGS, which tracks seismic activity across the country and gathers reports of who felt it, said the 10:23 a.m. quake was felt from Maine to Maryland. It was the biggest in the eastern U.S. since a 5.8 magnitude quake in Louisa County, Va., on Aug. 3, 2011, that was felt by millions of people and caused widespread damage that included the Washington Monument 80 miles away.

More than a dozen aftershocks were reported in the ensuing hours in the region, including a 4.0-magnitude quake early Friday evening, according to the USGS.

The State Emergency Operations Center was partially activated on Friday to help coordinate any emergency response that might be needed in towns and cities, said Brenda Bergeron, the deputy commissioner of the Division of Emergency Management and Homeland Security.

“We’re not seeing any significant damage,” Bergeron said during a news conference on Friday.

Connecticut officials said inspections were ongoing across the state to ensure the integrity of bridges and large buildings, utility lines, Millstone nuclear power plant and Bradley International Airport. Bradley briefly paused operations on Friday to perform inspections, Bergeron said.

Connecticut Department of Transportation spokesman Josh Morgan said crews mobilized out of an abundance of caution “to inspect critical bridge infrastructure in Connecticut.”

“At this time, there have been no reported concerns from the field,” Morgan said.

The DOT was paying particular attention to tall structures and stacked highways, such as the Gold Star Memorial Bridge, the Putnam Bridge, and the I-84/Route 8 Mixmaster in Waterbury.

“These are visual inspections looking for any movement to the surface or bearings of the structures,” Morgan said.

Similar precautions were being taken in other states. The Federal Aviation Administration issued a temporary “ground stop“ at Newark Liberty International and John F. Kennedy International airports to assess whether there was any damage.

Shaken in southeastern Connecticut

Cynthia Knight of Montville said the quake rattled her computer monitor and had her thinking there was a poltergeist in the house.

“It really was shaking. I was really surprised,” Knight said.

Shannon Ozkan said her entire house in Griswold shook, “and my kiddo jolted out of bed and came running down the hall.” Ozkan said she thought it might be the washing machine and had to double check that it was not running. She said the last time she felt an earthquake was years ago when she was living in Moosup.

Gale Goode, who lives on Route 1 in Groton, said she was lying in bed watching TV when the bed vibrated for four or five seconds. Living on the first floor of a two-family house, she thought about the house falling on her.

"I've never felt anything like this before," Goode said. "When they were paving the road on Route 1 it was really loud and noisy, but not like this."

Mark Matson, who lives on Starr Street in New London, said he works from home, and when the quake hit, everything in his office started to “oscillate.”

“It continued for about 30 second, decreasing in frequency until it ended,” Matson said in an email. “This is the second time I have been party to an earthquake, the last one when I was working in Danbury about 15 years ago.”

Chris Riley, a spokesman for Norwich Public Utilities, said in an online post that NPU followed its standard procedures for evaluating all of its critical infrastructure “for any damage or unusual conditions” across its natural gas, water, wastewater, or electric systems. Both the Occum and Greeneville dams were evaluated, Riley said.

“At this time, all NPU facilities and operations are normal,” Riley said. “We will continue to monitor things very closely in the hours ahead and provide any updates as necessary.”

Earthquakes in the eastern United States

Mitch Adelson, a cartographer with the USGS, said earthquakes in the eastern U.S. are rare but not altogether uncommon, especially smaller ones. Unlike the active faults in California, Adelson said the East Coast has remnants of older tectonic activity, or movement of the earth’s crust.

While the USGS uses seismometers to record seismic activity, Adelson said there is not yet a way to predict when they will occur. As far as the possibility of damage, Adelson said earthquakes in the 4 magnitude range have the potential to cause structural damage but not enough to cause “loss of life situations.”

Adelson said earthquakes in the eastern U.S. are known to be felt across great distances because of the rocks beneath us “transmit earthquake energy well.”

The quake came a little more than a week after the USGS reported a 1.8 magnitude quake in Ledyard.

Since 1950, the USGS said there have been just 13 earthquakes with a magnitude of 4.5 or higher within 500 kilometers of Friday’s quake. There have been 400 earthquakes of magnitude 3.5 or greater in eastern North America in the past 50 years, the USGS said. In addition to the 5.8 quake in Virginia in 2011, the USGS said there was a magnitude 5.3 earthquake in Au Sable Forks, N.Y. in 2002.

The USGS said Friday’s quake was the result of a “oblique reverse and strike-slip faulting at shallow depths in the crust,” or a shifting in the earth’s crust.

g.smith@theday.com