Much of southern Maine was shaken by an earthquake that struck off York Harbor at 10:22 a.m. Monday.
The U.S. Geological Survey said the quake, which had a magnitude of 3.8, was centered beneath the surface of the ocean 10 miles southeast of York Harbor.
That placed York's town hall close enough to receive a good shaking.
"We wondered if there was an explosion nearby," said Nicole Pestana, York's emergency management director.
She said there was concern about the many old windows in the town hall, but no damage was observed. Pestana said that as of late Monday morning, there were no other reports of major damage from the quake.
The Geological Survey says the quake was felt as far north as Augusta, west across much of New Hampshire and into eastern Vermont and as far south as Providence, Rhode Island, and the northeast corner of Connecticut.
Maine State Geologist Doctor Ryan Gordon said the precise cause of the quake will likely never be known. But he said it won't be because of any active "faults," like those out west.
"There's a lot of faults in Maine that existed back in geologic history. Most of them are millions of years old and we don't see any evidence that earthquakes are focused on those faults," he said.
Rather, Doctor Gordon said earthquakes here occur as the tectonic plate carrying Maine moves over the earth, occasionally causing cracking. It may also be the result of the earth still rebounding from the last ice age.
While the quake was centered off the coast, Gordon said it won't cause any disturbance in the ocean waters off New England.
