SOME Manitobans may have been shaking in their sleep the other night -- but not because of any nightmare.
In fact, a small earthquake rippled through Saskatchewan and western Manitoba just before 2:30 a.m. on Wednesday, with the temblor reportedly being felt in some parts of the province. "It's significant, mostly because it's in an unusual place," said University of Manitoba seismologist Andrew Frederiksen. "It's very unlikely to have done any damage."
The quake originated in a spot five kilometres beneath the ground near Esterhazy, Sask. -- or about 138 kilometres southwest of Dauphin -- and hit 3.3 magnitude, according to data from the United States Geological Survey.
But no fear, Frederiksen stressed. The quake doesn't point to any looming doomsday scenario here in the most geologically stable spot on the continent. "In Manitoba, we need flood insurance, not earthquake insurance," he quipped.
In fact, there is some history of mild quakes near the Esterhazy area -- as many as six small quakes have occurred there since 1990. Geologists believe the most likely cause is heavy potash mining in the area. "It doesn't mean a collapse in the mine or anything that dramatic," Frederiksen said.
"But the presence of mines does change loading conditions and could potentially lead to an earthquake."
Another theory holds the quakes may be triggered when groundwater dissolves salt deposits beneath the Saskatchewan soil.
A brief history of earthquakes felt in Manitoba
YEP, it's a brief history all right: According to National Resources Canada, Manitoba is the least likely province in the country to experience earthquakes. But we've felt a few tremors in our time from quakes originating elsewhere and sending shakes our way. Here are a couple of highlights:
1627-2010: A few scattered, minor quakes have struck Hudson Bay, on the northeastern tip of Manitoba, over the centuries. Experts note these are often a result of land that was compressed under glaciers springing back up over time.
1909: Newspapers at the time marvelled over what they believed was an "echo" from a large South American quake, which rattled doors and frightened residents throughout Winnipeg on the evening of May 16. It was the first time a quake had been known to strike the area. A recent review by the United States Geological Survey concluded the quake, estimated at 5.4 on the Richter scale, actually originated from the 300-kilometre Hinsdale fault line in Montana. It remains the largest historical earthquake known in North America's Great Plains.
2008: On April 10, a quake measuring 3.6 on the Richter scale shuffled its way through Manitoba and Saskatchewan. The source: the potash mine area near Esterhazy, Sask. It's one of six small quakes originating from that area in the last 22 years.