NORTHAMPTON — Sen. Jo Comerford was at home in Northampton on a Zoom call Friday morning when suddenly her home started shaking.

“I thought maybe it was ice falling off the roof,” Comerford said. “It was quite jarring.”

Leeds resident Jeffrey McLeod, however, had a different reaction to the earthquake that shook the densely populated New York City metropolitan area and rumbled throughout the Northeast.

“I knew it instantly. I’ve been through several little rumble earthquakes,” said McLeod, who was at the Northampton Recovery Center downtown at the time. “Then somebody called in from the Salvo House building asking if we had felt the building shake.”

The U.S. Geological Survey reported a quake at 10:23 a.m. with a preliminary magnitude of 4.8, centered near Whitehouse Station, New Jersey, or about 45 miles west of New York City and 50 miles north of Philadelphia. The agency’s figures indicated that the quake might have been felt by more than 42 million people in a region unaccustomed to it.

“Pretty weird and scary,” Shawn Clark said after feeling the quake in his 26th-floor midtown Manhattan office. Clark, an attorney, initially feared an explosion or construction accident.

Around the Pioneer Valley, some felt the ground tremble and some didn’t.

Greenfield resident Con Trowbridge said she was sitting by the window in her home on Keegan Lane when she felt what she described as a “thump,” which she thought was from someone dropping something off of a truck. Then she looked outside and saw a young maple tree shaking back and forth, despite the lack of any wind.

“The whole tree was rocking back and forth, the whole trunk of the tree was moving,” Trowbridge said. “‘That looks like an earthquake,’ I thought to myself.”

Others hadn’t felt the rumbling, but quickly learned about it from others. Jim Greco, the owner of the Bluebonnet Diner on King Street, said nobody in the diner had felt it when the earthquake struck, but he and others soon heard from family members who had.

In Amherst, Fire Chief Tim Nelson said a number of people called the department in the minutes following the quake, wondering what had just happened.

No damage was reported in the area.

It was not immediately clear what caused the earthquake. It occurred along the Piedmont, a plateau that runs along the east side of the Appalachian Mountains, and because that formation contains relatively old, dense rock, its shaking spread across hundreds of miles.

“The energy transfers pretty efficiently through those types of rocks,” David Wunsch, the Delaware state geologist, told The Washington Post.

New York City’s emergency notification system said in a social media post more than 30 minutes after the quake that it had no reports of damage or injuries in the city. Mayor Eric Adams had been briefed on the quake, his spokesperson Fabien Levy said, adding, “While we do not have any reports of major impacts at this time, we’re still assessing the impact.”

Amtrak said it was inspecting its tracks and had speed restrictions in place throughout the busy Northeast Corridor. New Jersey Transit posted on X that its train system was subject to delays caused by bridge inspections. The Philadelphia area’s PATCO rail line suspended service out of what it said was “an abundance of caution.”

At a coffee shop in lower Manhattan, customers buzzed over the unexpected earthquake, which rattled dishware and shook the concrete counter. “I noticed the door trembling on its frame,” said India Hays, a barista. “I thought surely there couldn’t be an earthquake here.”

New York Gov. Kathy Hochul posted on X that the quake was felt throughout the state. “My team is assessing impacts and any damage that may have occurred, and we will update the public throughout the day,” Hochul said.

Philadelphia police asked people not to call 911 about seismic activity unless they were reporting an emergency. Pennsylvania Gov. Josh Shapiro said state officials were monitoring the situation. A spokesperson for Connecticut Gov. Ned Lamont was unaware of any reports of damage in that state.

The shaking stirred memories of the Aug. 23, 2011, earthquake that jolted tens of millions of people from Georgia to Canada. Registering magnitude 5.8, it was the strongest quake to hit the East Coast since World War II. The epicenter was in Virginia.

That earthquake left cracks in the Washington Monument, spurred the evacuation of the White House and Capitol and rattled New Yorkers three weeks before the 10th anniversary of the Sept. 11 terror attacks.

Material from the Associated Press was used in this report.