Tremor tales: A look at New Brunswick's history with earthquakes

Thursday's earthquake near Grand Bay may have been startling, but in the grand scheme of the province's earthquake history, it wasn't exactly groundbreaking.

"New Brunswick is considered an area of moderately elevated risks in Canada compared to average," said geophysicist Karl Butler. 

The quake risk isn't as high as the Ottawa valley and the Quebec City area, and not as high as the west coast, but it's higher than many other parts of the country.

One of the biggest quakes ever recorded happened in 1982 between Newcastle, now Miramichi, and Plaster Rock.

That earthquake registered 5.7, causing cracks in some basements and roads. It was much stronger than Thursday's quake, which had a magnitude of 3.8.

The areas of St. Stephen, Miramichi, and Moncton have experienced the biggest quakes, but the province has been shaken by hundreds over the years. Most aren't felt, but will still be registered by a seismograph.

Butler said it's very important to track them all.

"Really the risk levels, or seismic hazards, are based largely on what we know from the past," he said.

"Because they're infrequent, and hard to predict, we have to rely on statistics of looking at catalogues of the past to better know what areas are at risk in the future."

New Brunswick has had substantial quakes every 30 years or so, but Butler said it hasn't always been easy to track them.

The province didn't start using seismographs until the 1960s, meaning every prior earthquake had to be assessed using newspaper reports dating back to the 1700s.

Geologists would painstakingly comb through the old newspaper accounts trying to figure out how far away people reported feeling the quakes. This helped determine the approximate magnitude.

So although the 1982 quake was the largest one recorded by a seismograph, another in St. Stephen in 1904 takes the title of largest-ever known, with a magnitude 5.9.

"It seemed that the shock was felt in St. Stephen more than anywhere else in the province. Several chimney pots were thrown to the ground. Some bricks were loosened from the walls of the Methodist Church, some panes were broken in the Chipman Memorial Hospital," reads one historical account.

More recently, Doaktown was rattled by a quake in 2009, downtown Fredericton in 2011, and a series of tremors struck McAdam in 2012. 

News archives also show there was an earthquake in Priceville in 1984 that gave residents quite a scare.

So Thursday's quake is not unusual, Butler said.

However, the residents of Grand Bay were lucky the magnitude was only 3.8. Butler said quakes start to cause damage when they reach 4.