Families displaced as earthquake rattles homes, nerves in southeastern Massachusetts

Don't be surprised if aftershocks are felt Monday, expert warns.

DARTMOUTH — An earthquake with a magnitude of 3.6 was registered near New Bedford on Sunday morning, the largest in New England in at least 57 years.

According to the U.S. Geological Survey earthquake recording map, the earthquake struck in Buzzards Bay just south of Dartmouth at 9:10 a.m. The USGS originally reported the earthquake's magnitude at 4.0, but downgraded it later Sunday morning.

Rumbling and shaking was felt throughout New England, and most acutely felt around New Bedford and Fall River, nearest the epicenter. Red Cross reports that multiple families in the New Bedford area were displaced as a result of the quake.

Fall River police Sunday morning announced that they "received numerous calls regarding minor damage inside people’s homes that consisted of items falling off of shelves."

"There were also reports of two street signs that became uprooted," Fall River police announced. "There have been no reported injuries associated with the earthquake."

Tiverton police also reported receiving many calls. "Good morning Tiverton.  Yes...we felt it too," a spokesperson said on Facebook. "Our dispatch center is getting flooded with calls. Please call for emergencies only. We will post more information as we receive it."

In Dartmouth, police reported that crews from Eversource had been dispatched to the town in case there were any power outages reported. But as of 11:30 a.m. Sunday, there were none in the area, according to the Eversource outage map website. National Grid also wasn't reporting any outages.

Three New Bedford homes in the area of Crapo and Nelson streets had to be evacuated due to structural damage, resulting in 10 families, a total of 22 people, having been displaced.

The New Bedford Fire Department reports that the bottom 4 feet of the chimney stack on the home at 202 Crapo St. had completely crumbled, and that pipes from the furnaces were leaning over. As a result, the gas had to be shut off in the building, leaving the residents without heat, hot water or stoves.

Firefighters said a home across the street, at 195 Crapo St., had the same damage as the home at 202 Crapo St., as the chimney stack had completely crumbled. The home's gas lines also had to be shut down.

While checking other houses in the area, firefighters said a nearby six-family home had multiple carbon monoxide leaks, and that gas service had to be shut off.

"If you see any signs of cracking, or certainly crumbling, of your chimney in the basement -- or anywhere in your house -- you should look up on your roof and check out your chimney," New Bedford District Fire Chief James Fortin said.

According to the Red Cross, the property manager for the homes is working with the agency to help provide lodging support for the affected residents.

After the earthquake Sunday morning, people immediately took to social media asking whether that was indeed an earthquake they felt, and not a truck passing by or their furnace failing.

But within minutes, geological websites were providing the answer: Yes, it was an earthquake, registering at 3.6 on the Richter scale, with the epicenter just off the coast of Dartmouth in Buzzards Bay, at a depth of about 10 kilometers.

People reported feeling the effects from the earthquake all across southern New England, and as far away as Vermont, New Hampshire and Long Island.

The earthquake lasted a matter of seconds.

The past 57 years on record, there have been 26 earthquakes in southern New England, and this was one of the largest, according to the Geological Survey. However, in areas of the world like California where earthquakes are far more common, this would be considered a minor quake, said Don Blakeman, a geophysicist for the federal agency.

"It's a bit unusual for southern New England, that's for sure," said Blakeman, based in Colorado, reached by phone on Sunday morning. "This may be the strongest one recorded in this area. A 3.6 in California is a fairly common occurrence and people don't think much about it. People not being accustomed to that are going to think it's a much bigger deal."

By 11:30 a.m., the Geological Survey received more than 19,000 reports of the earthquake through the "Did You Feel It?" tool on the agency's website. Several people in Brooklyn, New York, about 170 miles from the epicenter of the earthquake, reported feeling the quake.

"In terms of effects, a lot of people felt it," Blakeman said. "It wasn't strong enough to do structural damage. But close to the epicenter, things may have fell off shelves."

Blakeman said people shouldn't be surprised if they feel an aftershock in the coming day, a smaller earthquake caused as the crust of the earth adjusts to the effects of the main shock.

"It wouldn't be too surprising if we had a few after shocks," he said. "We can't predict it."

According to a metric the USGS uses to estimate potential damage and loss of life from earthquakes, there is a "low likelihood of casualties and damage" from Sunday morning's earthquake.

About an hour after the earthquake struck, Massachusetts Emergency Management Authority (MEMA) said there were no injuries or damage reported, and that there was no tsunami danger from the earthquake.

In the grand scheme of things, a 4.0 magnitude earthquake is not that strong.

An earthquake with a magnitude between 2.5 and 5.4 is "often felt, but causes only minor damage," according to a chart from Michigan Tech. There are about 30,000 earthquakes of this magnitude a year. A 4.0 earthquake is considered "light."

California has had nine earthquakes of at least 4.0 magnitude just since September.

But for New Englanders, an earthquake of this magnitude is a rare experience.

According to the Weston Observatory at Boston College, Sunday's earthquake was the largest in New England in eight years, since a 4.5 magnitude earthquake was recorded in Maine in October 2012.

More from the USGS website:

What is an earthquake?

An earthquake is what happens when two blocks of the earth suddenly slip past one another. The surface where they slip is called the fault or fault plane. The location below the earth’s surface where the earthquake starts is called the hypocenter, and the location directly above it on the surface of the earth is called the epicenter.

Sometimes an earthquake has foreshocks. These are smaller earthquakes that happen in the same place as the larger earthquake that follows. Scientists can’t tell that an earthquake is a foreshock until the larger earthquake happens. The largest, main earthquake is called the mainshock. Mainshocks always have aftershocks that follow. These are smaller earthquakes that occur afterwards in the same place as the mainshock. Depending on the size of the mainshock, aftershocks can continue for weeks, months, and even years after the mainshock!

What causes earthquakes and where do they happen?

The earth has four major layers: the inner core, outer core, mantle and crust. The crust and the top of the mantle make up a thin skin on the surface of our planet.

But this skin is not all in one piece – it is made up of many pieces like a puzzle covering the surface of the earth. Not only that, but these puzzle pieces keep slowly moving around, sliding past one another and bumping into each other. We call these puzzle pieces tectonic plates, and the edges of the plates are called the plate boundaries. The plate boundaries are made up of many faults, and most of the earthquakes around the world occur on these faults. Since the edges of the plates are rough, they get stuck while the rest of the plate keeps moving. Finally, when the plate has moved far enough, the edges unstick on one of the faults and there is an earthquake.

Why does the earth shake when there is an earthquake?

While the edges of faults are stuck together, and the rest of the block is moving, the energy that would normally cause the blocks to slide past one another is being stored up. When the force of the moving blocks finally overcomes the friction of the jagged edges of the fault and it unsticks, all that stored up energy is released. The energy radiates outward from the fault in all directions in the form of seismic waves like ripples on a pond. The seismic waves shake the earth as they move through it, and when the waves reach the earth’s surface, they shake the ground and anything on it, like our houses and us!

How are earthquakes recorded?

Earthquakes are recorded by instruments called seismographs. The recording they make is called a seismogram. The seismograph has a base that sets firmly in the ground, and a heavy weight that hangs free. When an earthquake causes the ground to shake, the base of the seismograph shakes too, but the hanging weight does not. Instead the spring or string that it is hanging from absorbs all the movement. The difference in position between the shaking part of the seismograph and the motionless part is what is recorded.

How do scientists measure the size of earthquakes?

The size of an earthquake depends on the size of the fault and the amount of slip on the fault, but that’s not something scientists can simply measure with a measuring tape since faults are many kilometers deep beneath the earth’s surface. So how do they measure an earthquake? They use the seismogram recordings made on the seismographs at the surface of the earth to determine how large the earthquake was (figure 5). A short wiggly line that doesn’t wiggle very much means a small earthquake, and a long wiggly line that wiggles a lot means a large earthquake. The length of the wiggle depends on the size of the fault, and the size of the wiggle depends on the amount of slip.

The size of the earthquake is called its magnitude. There is one magnitude for each earthquake. Scientists also talk about theintensity of shaking from an earthquake, and this varies depending on where you are during the earthquake.

With WCVB reports.