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10-10-2012, 05:23 PM
Join Date: Jan 2008
Location: Renfrew, ON.
Originally Posted by
I don't see why people are startled by this minor earthquake. Montreal witnesses earthquakes between 3.5-5 almost every 5 years or so and lesser ones each day, 99% of them are never felt.
The Valley of the St-Lawrence river lies between two mountains chains: the Laurentians and the Appalachians which were formed years ago by volcanoes and tectonic plate convection and movements. Many ancient fault lines are too be found along the river reminiscent once of the different plates which were colliding once and producing heat. This heat melted rocks and created mountains which in form erupted, releasing magma and forming the igneous rocks of the Canadian Shield (Northern Quebec and the Laurentians mountains). These inactive fault lines can become active sometimes triggering minor tremors like the one we witnessed today after midnight. The Charlevoix region in Quebec, for example, can see earthquakes of up to 7.
The soil in the Valley was also compacted by years of glacial erosion. The land tends to lift which also causes minor tremors. Mont-Royal for example, is a volcanic intrusion caused by the uplift motion of the soil.
Montreal and the St-Lawrence Valley is the second most active seismic zone in Canada after BC. Tall Buildings in Montreal are designed to withstand earthquakes of 6-7 magnitude.
You're either a geologist, or whatever.
Or you have one of those cards that tells you the history of a certain region.
It could have been caused by an under water volcano, but not likely.
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