Aftershock Rattles Southern Maine Coast After Stronger Quake

YORK HARBOR, Maine — A magnitude 2.0 earthquake struck off the coast of southern Maine early Wednesday morning, marking the latest in a series of seismic events that have rattled the region. The quake, detected at 3:15 a.m., occurred just 5.5 miles southeast of York Harbor, nearly the same location as a stronger magnitude 3.8 earthquake on Monday.

New Hampshire State Geologist Shane Csiki confirmed that Wednesday’s tremor was likely an aftershock of Monday’s larger quake. “The possibility exists for some additional aftershocks,” Csiki said. “The magnitude of those aftershocks should decrease with time.”

Monday’s earthquake, which was felt across New England and as far south as Pennsylvania, was the fifth-strongest on record in Maine, according to the U.S. Geological Survey (USGS). The quake, centered about six miles underground, caused no significant damage or injuries but prompted more than 40,000 people to report their experiences to the USGS. In contrast, only about 20 people reported feeling Wednesday’s aftershock.

Csiki explained that Monday’s earthquake was caused by a fracture or break in the rock, which increased stress on adjacent rocks. Aftershocks occur as the rocks gradually release and settle. “This is very typical, an aftershock two days later,” said John Ebel, a scientist at the Weston Observatory at Boston College. He added that aftershocks could continue for a week or more, with the possibility of a larger one, potentially up to magnitude 3.0.

Maine typically experiences several noticeable earthquakes each year. In 2024, four earthquakes with epicenters in the state were strong enough to be recorded by the Maine Geological Survey. The strongest, a magnitude 2.8 quake, occurred in West Gardiner on July 28. The Richter scale‘s logarithmic nature means Monday’s quake had ground motion 10 times greater than the West Gardiner event and more than 10 times stronger than Wednesday’s aftershock.

While earthquakes in New England are relatively rare, they are not unprecedented. Ebel noted that a quake like Monday’s occurs roughly once every 10 to 20 years in the region. Despite the recent activity, experts emphasize that there is no cause for alarm, as the aftershocks are expected to diminish in intensity over time.