The first weeks of 2023 have not been kind to Bentley.
The small mixed-breed dog is in a near-constant state of agitation thanks to ongoing seismic activity below the Dedham home he shares with his humans, Mike and Linda Curcio.
For the last month the retired couple and Bentley have felt the earth vibrate and boom under their feet thanks to earthquakes too small to cause damage, but strong enough to notice.
“These microquakes are something that are just at or even below the detection limit of earthquake detecting instruments,” said Henry Berry, senior geologist with the Maine Geological Survey. “Here where we are not used to earthquakes they can be really disconcerting.”
There have been 51 of these small earthquakes, referred to as an “earthquake swarm,” in Dedham in the last two weeks, according to Berry. While the phenomenon is actually quite common in Maine, it’s rare for the quakes to happen in an area as populated as Dedham. The ongoing seismic activity is proving to be surprisingly disruptive to residents and their dogs, who are even more sensitive to the quakes.
The strongest was a magnitude 3.3 quake on Jan. 14 immediately followed by more than two hours of 15 smaller microquakes less than magnitude 2.
The Curcios had been in their house for just a few weeks when the ground started shaking under it last November.
“We had just built our house and moved in,” Mike Curcio said. “It sounded like rock blasting with a boom [and] each time we ran outside and ran around to see if anything had smashed into the house.”
It’s a valid fear. The Curcios’ house is at the bottom of a decline leading to Phillips Lake. Uphill is a large boulder that, if shaken loose, would carve a path directly through the house on its way into the lake.
The odds of that happening are pretty slim, but are of little comfort to Bentley, according to Mike Curcio.
“Every time he feels or hears one of these quakes, [Bentley] has an out of body experience,” Mike Curcio said. “He is getting used to the smaller ones, but the dogs across the street start barking when it’s happening.”
Mike Curcio looks out his window while talking about the microquakes he and his wife Linda have been feeling recently in their Dedham home. Their dog Bentley is on edge from the ongoing seismic activity below. Credit: Linda Coan O’Kresik / BDN
Not only are Bentley and the other dogs and humans on Phillips Lake feeling the earth’s vibrations, they are hearing them, too.
“The first time we heard it, we thought it was a sonic boom,” Mike Curcio said. “Our neighbor thought his furnace had exploded.”
What they are hearing is the release of pressure being created far below the surface of the earth.
“It’s all about [continental] plate motion,” Berry said. “It’s the plate underneath us that is the part causing the trouble.”
Maine sits on top of the North American Plate along with the rest of North America, Greenland, part of Iceland and part of Siberia. Like the other plates on the planet, it’s in constant motion clipping along at roughly 2.5 centimeters a year heading southwest.
It is not a smooth trip.
Much like a jarring car ride over potholes and frost heaves on a rural Maine road, the North American Plate is bouncing — albeit slowly — over the rough surface of the earth’s crust miles below.
“People are surprised when you equate noise with an earthquake,” Berry said. “But the booming sounds are typical of the low intensity quakes like they are getting in Dedham.”
They are often described as sounding like rushing wind or snow sliding off a roof.
“The plate movement builds up pressure that has to go somewhere,” Berry said. “It’s creating seismic waves that are traveling through solid rock not making a sound until they hit the air [and] when that wave hits the surface of the ground it explodes into the air.”
Linda Curcio has been in contact with Berry and has become something of a microquake citizen scientist, recording the date and time she hears or feels one.
Pictures hang crooked on the walls of the Curcio’s Dedham home from the daily microquakes they have been experiencing the last few weeks. These earthquakes are too small to cause any damage, but strong enough to notice. Credit: Linda Coan O’Kresik / BDN
So far she’s logged at least one microquake a day since the start of the year. Making note of when and where these microquakes are happening will help geologists who are studying the phenomena, according to Berry.
“We know what causes them in general, but we would like to know more and to know more we need more detailed information,” Berry said. “We know a lot of earthquakes out west in places like California but there is not a lot of data about them here in Maine.”
Linda Curcio is a graduate of the University of Maine and summered at Phillips Lake growing up. No one back then ever mentioned experiencing earthquakes.
While the microquakes may be new to Dedham, there is centuries worth of documentation of them occurring in Maine.
“If you look at all the records we have that go back to journals of the 1700s, it’s apparent they have happened all over the place in Maine,” Berry said. “They are really interesting.”
It would seem there is at least one resident along Phillips Lake who does not share that enthusiasm.
“I’m fascinated by them,” Linda Curcio said. “Unfortunately, Bentley spends hours shaking after each one and he is really not happy when they happen.”
