Ground motion as recorded by the Western Observatory with seismic waveforms highlighted surrounded by white boxes along the 09:00 horizontal (blue) line. | Courtesy Western Obervatory at Boston College and Groton Emergency Management)
December 3, 2013 12:09PM
By MICHAEL SOUZA
Sun Staff Writer
If you live in Stonington, North Stonington or northern Groton and heard something that sounded like explosions on Friday, it turns out that you were experiencing an earthquake. Between 9 and 10 a.m. Friday, police and fire departments from all three towns received many 911 calls reporting explosions in the northern parts of the area. The calls put police and fire crews from all three towns on the roadways looking for evidence as to the origin.
“Groton and Stonington received a lot of calls and I guess it was felt in North Stonington,” said Joseph R. Sastre, director of the Office of Emergency Management in Groton. “Just about everyone was out there looking for anything we could find.”
Police looked everywhere in the town’s northern areas and found nothing, no traces of smoke or fire.
“We also called the State Police and the fire marshal to see if anyone could be blasting. We checked with the military and the Federal Aviation Administration for a sonic boom. There was nothing.”
A call to the National Weather Service early Friday indicated no seismic activity.
Stonington officials were also involved in the search. “We’re looking into it but don’t have any answers yet,” said First Selectman Edward Haberek Jr. on Friday.
The incident remained a mystery until Monday morning, when Sastre heard back from the Western Observatory at Boston College. The observatory was closed over the holiday weekend.
At about 9:05 a.m., and again at 9:42 a.m. the area was struck by a magnitude 1.8 earthquake. Both were very shallow, and therefore audible events. “They explained that it’s not uncommon for explosions to be heard in a situation such as this,” Sastre said.
The observatory also reported the center epicenter of the earthquake to be in the vicinity of Routes 184 and 117 in Groton. Data from the U.S. Geological Survey put the magnitude of the quake at 2.2, at a depth of about 1.8 miles.