Earthquake activity in Maine calmed down over the weekend after a busy start to the new year which featured many quakes. Twelve earthquakes have rattled portions of Maine so far this month, with most of the seismic activity centered over Rainbow Lake northwest of Millinocket and the others just south and east of Bangor. Two quakes also struck just off-shore between the coastal communities of Bristol and Saint George. The last earthquake to strike Maine hit early Saturday morning and there have been none others since.
The strongest earthquake of the bunch this month was a magnitude 3.3 quake which struck just outside of Dedham east of Augusta. That earthquake, which struck in the morning of January 14 generated more than 140 reports of shaking to the USGS by way of their “Did you feel it?” reporting tool on their earthquake website. According to USGS, the event was rated a IV (4) on a Roman Numeral scale of earthquake shaking intensity from I (1) to X (10). USGS considered an IV earthquake to have light shaking but no damage.
Most of the other earthquakes which shook Maine from January 5 to January 13 have been light, ranging from 1.6 to 2.0 magnitude events.
While not famous for their earthquakes, Maine does get them from time to time. Last winter/spring, several earthquakes also hit the state. On April 2, 2022 a magnitude 2.0 earthquake struck about 7 miles southeast of Waterville, near the Winslow-China town line. On March 8, a magnitude 2.1 earthquake struck about 2 miles north of Tunk Lake in eastern Hancock County. On February 12, a magnitude 2.4 earthquake struck 12 miles west of Houlton; some locals reported feeling shaking then. On February 4, a magnitude 2.9 event was widely felt in the Bethel area of western Maine, 8 miles from the epicenter in Gorham, New Hampshire. People up to 25 miles away from the epicenter of that earthquake felt it in Maine. Two earthquakes of a 2.0 magnitude hit on January 17 ; one was 2 miles west of Springvale, the other was about 1/2 mile south of Springvale.
The strongest earthquake to strike Maine in the last 10 years was a magnitude 4.5 event on October 16, 2012 in East Waterboro, about 13 miles northwest of Saco.
According to the Maine Geological Survey with the Department of Conservation, seismic activity in Maine is typical of the Appalachian region of northeastern North America. “There is a low but steady rate of earthquake occurrence,” they report, adding that “The earthquakes are presumably caused by modern stress being released occasionally along zones of weakness in the earth’s crust, but a more specific cause for the earthquake activity is not known.”