Did you feel it?
A 3.8 magnitude earthquake off York Harbor, Maine, shook Seacoast New Hampshire, southern Maine and much of New England Monday. It caught the entire region by surprise, public safety dispatch centers were flooded with calls. Officials in numerous communities reported there were no injuries or property damage.
The earthquake prompted lots of questions, such as: Has it happened before? Will it happen again? Could there be aftershocks? We posed this line of questioning and more to two University of New Hampshire professors who helped answer them, along with data from the U.S. Geological Survey.
A 3.8 magnitude earthquake occurred off York Harbor in Maine on Monday, Jan. 27, 2025. This map from the United States Geological Survey shows the exact location of the epicenter in the Atlantic Ocean.
How many earthquakes have there been in Maine and New Hampshire in recent years?
A review of USGS data found there have been more than 50 earthquakes since 2000 in Maine and New Hampshire or off the shores of the two states. Monday’s quake is listed as the third-highest magnitude earthquake in the two states this century, with a 4.7 magnitude earthquake just west of Hollis, Maine, in 2012 taking the top spot.
VIDEO: See video from the Maine earthquake at Nubble Lighthouse, York Harbor Beach
Monday’s earthquake was the third in the York area in recent years, joining a 2.8 magnitude earthquake in March 2008 off York Beach and another 2.9 magnitude earthquake off the beach in June 2010, according to USGS records.
How often do earthquakes occur in Maine and New Hampshire?
Two University of New Hampshire earthquake experts reported smaller earthquakes that aren’t as strongly felt occur in Maine and New Hampshire from time to time, but both agreed Monday’s earthquake was a rare event.
“Generally in New England … we see these (somewhat larger) earthquakes every five-ish years or so. For the region as a whole, they happen relatively infrequently, but it’s not that unusual,” said Sophie Coulson, assistant professor of earth sciences at the University of New Hampshire. “It’s more unusual for us to have one that is actually felt by a lot of people.”
Why did the earthquake happen?
Between 300 million and 500 million years ago, the Appalachian Mountains were formed when two continents collided. The New England region has faults from that time period, or “pre-existing planes of weakness that are running through the earth,” according to Coulson.
However, Coulson believes Monday’s earthquake occurred because of pressure in the Atlantic Ocean being pushed west toward land and away from the Mid-Atlantic Ridge, an underwater range. The Mid-Atlantic Ridge spreads between 0.8 to 2 inches per year, per the National Oceanic and Atmospheric Administration.
“(New Hampshire and Maine) sit on the North American Tectonic Plate. That same plate stretches all the way out to the Mid-Atlantic Ridge, where the tectonic plates are being pushed apart,” Coulson said. “We would call this earthquake an ‘intra-plate’ earthquake as it occurred in the center of the tectonic plate rather than at the edge of the plate where one plate meets another.”
Where did the earthquake happen?
The epicenter of Monday’s earthquake was roughly 10 kilometers southeast of York Harbor. The UGSS noted it occurred 13.2 kilometers below the surface of the Atlantic, though there was no threat of a tsunami afterward.
Why was there no structural damage from the earthquake?
People around the Seacoast, southern Maine and in Strafford County reported feeling the quick quake on Monday, in addition to people farther inland in Maine and New Hampshire and elsewhere in New England. Locals shared their experiences and the sound heard during the earthquake, with many comparing it to an explosion or the sound of a large vehicle striking a structure.
Majid Ghayoomi, a UNH professor of civil and environmental engineering, said some structural damage to buildings and personal and public property could have occurred if the epicenter was closer to shore.
Earthquake maps: See where Maine earthquake epicenter was, seismic intensity map
It’s possible actual damage to homes, businesses and public and private property could have occurred if the earthquake’s energy came out with more velocity and acceleration, according to Ghayoomi.
Will there be aftershocks from Monday’s earthquake?
If the region were to receive an aftershock from Monday’s earthquake in the coming days, it may not even be noticeable.
“We would typically expect aftershocks to be smaller than the ‘mainshock’ event, so if there are aftershocks from this event over the next hours or days, they may be small enough that we don’t actually feel them,” Coulson said. “Aftershocks happen as the rock that has been displaced in the main earthquake slowly settles and readjusts afterwards.”
Neither Coulson nor Ghayoomi expect aftershocks, nor do they expect another similar earthquake to happen for some time.
“Small earthquakes are often not bad because they increase people’s awareness,” Ghayoomi said. “Small earthquakes, two good things about them (are), people become more ready and (the earthquakes are) releasing the energy.”
The USGS on Monday night said there is a 13% chance of at least one magnitude 3.0-plus aftershock in the next week.
Why was the earthquake so loud?
The loud sound associated with the earthquake is indicative of the amount of pressure built up that was released and the lack of depth at the epicenter, he said.
“When you have a (loud) noise, that means the earthquake’s depth is shallow,” Ghayoomi said.
On Star Island, one of the nine Isles of Shoals off the New Hampshire coast, there were “no apparent changes” after the earthquake passed, according to the island’s winter caretaker, Alexandra de Steiguer.
“At first I thought an airplane had hit the house, there was a loud roar and a giant thump and the house shook alarmingly for only a moment,” she wrote on Facebook. “The geese took frantic flight as it was happening, while I ran to all parts of the house, including underneath, to be sure nothing had been hit or exploded … while doing so I started to suspect it might be an earthquake. Glad it was ‘only’ that!”
“There are small faults around us. They are not major plates that cause big earthquakes. But this energy that accumulates during the year needs to be released,” Ghayoomi added.
“When earthquake waves (shaking) reach the surface, they can be transferred to the air and become sound waves,” Coulson said in an email Monday afternoon. “Then we can often hear the sound all around us. If you are close to the earthquake, when these high frequency waves first reach the surface, they can sound like a ‘boom.’”
“At these small magnitudes it is unlikely that much structural damage would occur,” Coulson said. “We would expect damage from a bigger earthquake – magnitude 5 or 6, for example.”
What other earthquakes have been felt in Maine and New Hampshire in recent years?
In April 2024, a 4.8 magnitude earthquake recorded in Whitehouse Station, New Jersey, was felt regionally, including in Seacoast New Hampshire.
In local communities, other earthquakes have been recorded by the USGS. In January 2000, a 3.0 magnitude earthquake was reported in Fremont, New Hampshire, while a 2.7 magnitude rumble happened in East Kingston, New Hampshire in February 2018. Old Orchard Beach in Maine has also experienced earthquakes, including a 2.7 magnitude event 50 kilometers east of the town in March 2020.
This article originally appeared on Portsmouth Herald: Earthquake in Maine, NH: Will there be aftershocks? Experts explain
