According to the US Geological Survey, Maine had three earthquakes with a magnitude of 3 point 0 or higher between 2010 and 2015..
New Hampshire has had 1, Vermont hasn’t had any.
Now compare that to a place like California where there were 130 in 2015 alone, or Alaska which had more than 9 thousand earthquakes with a magnitude of 3 or more in that six year time span, an average of 15 hundred per year.
While Maine’s numbers look small in comparison to states like Alaska, Hawaii or California, earthquakes do happen here, but we haven’t had any major activity since before the dinosaurs.
“We’re not on a major, active fault zone,” said Dr. Bob Nelson Professor of Geology at Colby College. “Although we have faults criss-crossing all over the state, most of them haven’t moved in hundreds of millions of years.”
“They all developed under a totally different geological setting 350-400 million years ago when continents were colliding in our part of the world,” said Maine State Geologist Robert Marvinney. “That’s not happening now so all those faults are inactive, even though we map them on geologic maps they are not, we have not been able to link a modern earthquake with one of those faults.”
While California, and Alaska are at the edges of the Earth’s tectonic plates, Maine basically sits in the middle of the North American plate that stretches to Iceland.
“We’re sitting on this plate, it’s moving right now. North America and Europe are separating by about a centimeter a year, so it’s about the rate that your finger nail grows that’s how quickly it’s moving, but it doesn’t move smoothly, it moves in jerks, and those are earthquakes,” said Marvinney “Although most of the earthquake activity happens at the boundaries of the plates, the whole plate is moving, and it doesn’t move in one smooth easy action, it moves by these little motions that we recognize as earthquakes the rocks break at depth and move and are jostled, and that generates, that releases energy into the crust that recognize as earthquakes.”
While Maine only has those three earthquakes registering at more than a magnitude 3 from 2010-to-2015, there was a maginitude 4.0 quake in Hollis Maine in 2012, we get more than that, just they are hard for people to notice because they aren’t very big.
“We have statistics that say 10-to-12 a year but some years we have more,” said Marvinney. “Some years we have less, it’s not this even distribution over time.”
Maine has a number of geologists working and teaching in the state, but no one specifically dedicated to earthquakes.
“It’s like having an oil geologist here,” said Dr. Nelson. “There’s no chance of finding oil or natural gas in Maine so there’s no reason to have earthquake people here.”
Marvinney, the Maine State Geologist said there does seem to be more activity in places like Eastport and Milo, but those are still nothing of concern. “We can have a period where there might be a dozen earthquakes in one location and I’ve never seen it lead up to something bigger, there is a zonal weakness and it gets set off by our plate motion and there’s a number of small earthquakes, and then it quiets down.”
Marvinney and Professor Nelson both said the geology of the planet would have to change drastically for Maine to be a location of a major quake.
“The likelihood of a large earthquake in Maine is very, very slim,” said Dr. Nelson. “I mean you are more likely to win the Megabucks and be hit by lightning in the same day, probably, but that doesn’t mean that there’s no chance and if you don’t monitor for things how do you know what happens.”
And while there is very little chance of “The Big One” hitting the Pine Tree State there are still a number of recording sites around Maine.