N.E. jolted from afar
Canadian temblor prompts local evacuations
A 5.0 magnitude earthquake that hit the Ontario-Quebec border yesterday was felt more than 300 miles away in Massachusetts, forcing emergency officials to evacuate buildings and startling office workers and apartment dwellers.
The earthquake, which struck about 36 miles northeast of Ottawa, did not cause any property damage or injuries in New England or Canada, but police officers and firefighters in several area towns said they received numerous 911 calls describing shaking floors and trembling office cubicles.
In Brookline, at least 100 people had to evacuate a 10-story medical office building after someone on the seventh floor called 911 to say chairs were moving.
Around the same time in Wellesley, firefighters evacuated dozens of people from a three-story office building after employees reported the floor was shaking. Patients also had to be evacuated from a medical office in the building.
“I thought I was dizzy, but then I noticed the plants in my office were moving around the floor,’’ said Anton Reinert, an employee in the Wellesley building. “It felt like I was on a train or a boat that was shaking and rocking.’’
In Medford, Jen Moore, who works on the fourth floor of a corporate office building on Cabot Road, said she and her co-workers felt the tremor as their cubicles shook around them.
“It felt like we were on an amusement park ride,’’ she said.
Others said they felt nothing or just dismissed the shaking, thinking it was a large passing truck.
“It was weird,’’ said Omar Mejia, 25, of Roslindale, whose bed rocked back and forth. A framed picture of his girlfriend shook slightly on the wall.
“I don’t know how to describe it,’’ he said.
The earthquake hit at 1:41 p.m., about 9.8 miles below the surface, said A.B. Wade, a spokeswoman for the US Geological Survey. The agency calculated that the epicenter was in a wildlife preserve.
It was the second time in recent weeks that the Boston area was affected by unusual events in Canada. Last month, the city’s skyline was obscured by smoke coming from 50 forest fires in Quebec.
The last time the Boston area was affected by an earthquake of this size was in April 2002, when a 5.1 magnitude temblor struck the Adirondack Mountains in New York, said John Ebel, director of Boston College’s Weston Observatory and a geophysics professor.
But not many people noticed because it struck before 7 a.m. on a Saturday, he said.
Yesterday’s event may seem minor when compared with the earthquakes that have devastated other parts of the world, such as Haiti, but it is significant, Ebel said.
“One of the things it does is serve as a reminder that we do have earthquakes in our part of the world,’’ he said. “What it does mean is earthquake provisions, building codes, earthquake safety drills in school are things we should be thinking about in the Boston area and in New England and not saying, ‘oh that’s what happens in Los Angeles.’
“The chances are high enough that we do need to take it seriously.’’
New England sits in the middle of the North American plate, which would appear to make the area more stable than California, which is cleaved by the San Andreas fault. That fault separates the Pacific and North American plates, which slowly grind past each other.
But the Northeast is still vulnerable to earthquakes, scientists say.
One theory is that the North American plate, which is slowly moving away from Europe and Asia, is pushing against the Pacific plate. That movement could cause pressure against ancient fault lines in the North American plate, resulting in earthquakes.
But scientists still do not know exactly what causes these quakes, said Alan Kafka, associate director of the Weston Observatory and a geophysics professor.
“It remains a mystery,’’ he said.
Ebel and Kafka said they did not feel tremors at the observatory, a small, brick building off Concord Road, where the professors hosted an open house yesterday.
Kafka said he was lecturing to about half a dozen visitors on earthquakes when he looked at one of the office computers, which showed a seismogram. The horizontal lines on the screen, which had been fairly flat, had spiked.
“It’s very exciting,’’ said Kafka, who has been studying New England earthquakes for 30 years. “It’s hard not to get excited.’’
In terms of earthquakes, a 5.0 is moderate, compared with a 7.0 — the size of the earthquake that devastated Haiti in January — which is considered a large earthquake. An 8.0, is a great earthquake, he said.
But if a 5.0 were to hit Boston, there could be significant damage, Kafka said.
The city has many old brick buildings that were built before stricter codes. Many are also built on soft ground, such as river bottoms and landfill, which make the foundations less stable.
“A 5 in Boston would be significant,’’ Kafka said. “We do worry about a 5 in Boston. It’s not trivial.’’
Martin Finucane of the Globe Staff and Globe correspondents Jason Woods, Katrina Ballard, Brock Parker, and Stefanie Geisler contributed to this report. Maria Cramer can be reached at firstname.lastname@example.org. Shana Wickett can be reached at email@example.com.