NEW JERSEY - A 2.9-magnitude earthquake aftershock was reported in Somerset County, New Jersey Saturday morning.
The U.S. Geological Survey said the report came around 9:50 a.m. in Gladstone.
The epicenter was near Whitehouse Station, which is nearly 45 miles west of New York City.
On April 10, a 4.8-magnitude earthquake shook New York City and the Tri-State area.
The event was followed by a magnitude 4.0 aftershock later that evening, with the epicenter near Gladstone in New Jersey.
Experts say small aftershocks can happen days or even weeks after a primary event.
The 4.8-magnitude earthquake was the largest in the Tri-State area since 1973.
Earthquake in New Jersey
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.
Check out the USGS interactive map to see if your area was affected.