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

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.

Smith College geosciences professor Jack Loveless said he didn’t feel the quake, nor did most of the students in the science buildings near Northampton’s Paradise Pond. But people in the college’s buildings along Elm Street felt it.

Loveless believes that’s due to differences in the substrate, with areas built on bedrock less likely to transmit the earth shaking than places built on sediment.

“Similar to 2011, I found out about it from my wife,” he said.

The quake was consistent with notable East Coast earthquakes, he said, which are rare because, unlike the West Coast, the region is a long way from any major tectonic plate boundary.

The 2011 quake, with a magnitude of 5.8, was 10 times stronger than Friday’s rumble.

People from Baltimore to Boston and beyond felt the ground shake Friday. The temblor severely damaged three multifamily homes in Newark, New Jersey, displacing nearly 30 residents. Officials around the region were checking bridges and other major infrastructure, some flights were diverted or delayed, Amtrak slowed trains throughout the busy Northeast Corridor, and a Philadelphia-area commuter rail line suspended service as a precaution.

Pictures and decorative plates tumbled off the wall in Christiann Thompson’s house in Whitehouse Station, she said, relaying what her husband had told her by phone as she volunteered at a library.

“The dogs lost their minds and got very terrified and ran around,” she said.

Whitehouse Station Fire Chief Tim Apgar said no injuries were reported, but responders fielded some calls from people who smelled gas. Nearby, the upper portion of the 264-year-old Col. John Taylor’s Grist Mill historic site collapsed onto a roadway, according to Readington Township Mayor Adam Mueller.

In a 26th-floor midtown Manhattan office, Shawn Clark felt the quake and initially feared an explosion or construction accident. It was “pretty weird and scary,” the attorney said.

Aftershocks were reported hours later in a central New Jersey township, producing some reports of damage and items falling off shelves, Hunterdon County Public Safety Director Brayden Fahey said.

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.”

Friday’s quake was felt as far away as Maine, where “it felt like the floor was almost doing the wave” in Meghan Hebert’s South Portland apartment. Some Vermont and New Hampshire residents initially figured it was snow falling off their roofs or plow trucks rumbling by.

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.