NEWRY – Maine state geologist Robert Marvinney said Thursday that experiences reported by people who felt or heard the morning’s quake are typical of a 2.2 earthquake.

He wasn’t surprised by the lack of damage reports and didn’t expect any.

“Typically, damage does not occur until an earthquake reaches magnitude 5, about 20,000 times more powerful than this morning’s earthquake,” Marvinney said.

He also ruled out dynamite blasting at area subdivisions or mines, to which some initially attributed the explosion of sound.

“A dynamite blast looks different. A 2.2 earthquake is way beyond what dynamite would look like. If the blasting was done wrong – like the mats weren’t on properly – you’d get a big air shock and it would shake a house, but it would do almost nothing in the ground,” Marvinney said.

Statewide, he said Maine regularly experiences small earthquakes of this size, maybe six to 10 a year. Unlike California and other parts of the country,

Maine earthquakes are not related to any mapped geological faults. Those are hundreds of millions of years old in this area.

Maine’s quakes are either related to the ongoing slow westward movement of the North American tectonic plate, which stretches from Iceland through Maine to the edge of California, or to the gradual rebound of the Earth’s crust after the melting of the last great ice sheet about 12,000 years ago, Marvinney said.

The area’s last significant earthquake measured 4.8 on the Richter scale. It was 1973 and the epicenter was in Bowmantown Township, on the Canadian border in northern Oxford County.


Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.