Why Are Earthquakes Happening in New York and New Jersey?

New York|What to Know: Why 2 Quakes Jolted New York and New Jersey Recently

A 2.7- magnitude earthquake hit northern New Jersey on Tuesday, just days after a 3.0-magnitude quake struck the same area on Saturday, shaking parts of the state and New York City.

The recent temblors were classified as “weak,” according to the U.S. Geological Survey’s Mercalli Intensity Scale. Still, they were a shock to New Yorkers and New Jerseyans generally unused to the earth shaking beneath them.

But several experts consulted by The New York Times all agreed: The two quakes were not out of ordinary for the area. And a bigger one is not out of the question.

Since 1900, there have been 355 earthquakes in the New Jersey area with a magnitude of 1.0 and above, according to the U.S. Geological Survey. In those 125 years, only 20 earthquakes have had a magnitude of 3.0 and above that people can actually feel.

But the two recent quakes are not surprising, given a larger 4.8- magnitude earthquake last year that jolted New York and New Jersey and sent tremors from Philadelphia to Boston. Andrew Lloyd, an assistant research professor at Lamont-Doherty Earth Observatory at Columbia University, said that the two earthquakes could be aftershocks from that bigger one.

And it’s likely, researchers say, that the earthquake that occurred Tuesday was triggered by Saturday’s event.

“I’m not concerned because I’m an expert,” said Folarin Kolawole, an assistant professor of geology at Columbia University. “But I understand the disturbance that earthquakes like this create for common people.”

Residents of New York and New Jersey can expect to feel a slight rumble from minor earthquakes in the future, according to Dr. Lloyd.

He explained that California is at a tectonic plate boundary, where earthquakes occur more frequently as plates collide and slide past each other. The New York region is not, but New Jersey and New York are at an intraplate setting — at or near the center of a tectonic plate, where earthquakes are still possible.

“They should expect similar-sized earthquakes going forward,” he said.

But Dr. Kolawole said major earthquakes — defined as those with a magnitude of 5.0 or above — could happen in the New Jersey and New York area, and he stressed the importance of monitoring.

“We have ancient faults in the New York/New Jersey region that are active and can sleep,” he said. “There’s a potential for a greater than magnitude 5 earthquake.”