Why earthquakes are less common along East Coast than the western US

The biggest Eastern quakes usually occur along the mid-Atlantic Ridge, which extends through Iceland and the Atlantic Ocean.

Friday, April 5, 2024

Lee Goldberg explains the earthquake and its aftershocks

Lee has the details of the historic earthquake in New Jersey on Friday morning.

NEW YORK (WABC) -- An earthquake centered between New York and Philadelphia shook skyscrapers and suburbs across the northeastern U.S. for several seconds Friday morning, causing no major damage but startling millions of people in an area unaccustomed to such tremors.

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 over 42 million people might have felt the rumbling.

Earthquakes are less common on the eastern than western edges of the U.S. because the East Coast does not lie on a boundary of tectonic plates. The biggest Eastern quakes usually occur along the mid-Atlantic Ridge, which extends through Iceland and the Atlantic Ocean.

Quakes on the East Coast can still pack a punch, as its rocks are better than their western counterparts at spreading earthquake energy across long distances.

"If we had the same magnitude quake in California, it probably wouldn't be felt nearly as far away," said USGS geophysicist Paul Caruso.

A 4.8-magnitude quake isn't large enough to cause damage, except for some minor effects near the epicenter, the agency posted on X.

RELATED | Here are notable earthquakes felt in the New York City region

Professor Matt Gorring explains the science behind the earthquake.

Robert Thorson, a University of Connecticut earth sciences professor, said the quake resulted from the constant compression of the earth's hard, brittle crust in New Jersey.

"It's like having a big block of ice in a vise, and you are just slowly cranking up the vise," he said. Eventually, you're going to get some crackling on it."

This is the strongest earthquake since 1884 for the greater New York City metro area, or in nearly 140 years, and this is the strongest New Jersey earthquake since 1783 when a magnitude 5.3 occurred.

Almost an hour later, at 11:20 a.m. a 2.0-magnitude aftershock was felt near Bedminster, New Jersey. A second aftershock, a magnitude 2.2, occurred at 1:32 p.m. a few miles south of the first aftershock in Somerset County.

According to the forecast, there is still a 34% chance that there could be an aftershock of 3.0 or greater and there is a chance for aftershocks for about a week after the initial earthquake.

"Now that the aftershock did drop in magnitude to a 2.0, the percentage chance of seeing an aftershock greater than that starts to drop as well," said meteorologist Dani Beckstrom.

Meteorologist Dani Beckstrom has more on the aftershock and liklihood of experiencing more.

Earthquakes along the Atlantic Seaboard are uncommon but not unheard of. Earthquakes with magnitudes near or above 5 struck near New York City in 1737, 1783, and 1884.

While earthquakes in this region may be rare, earthquakes can happen anywhere. About 75% of the U.S. could experience a damaging earthquake.

(The Associated Press contributed to this report.)