Montreal actually sits on a continental “weak spot,” explained Christie Rowe, a professor of Earth and Planetary Sciences at McGill University and the Canada Research Chair in Earthquake Geology, making it prone to seismic activity.
“The St. Lawrence lies in a very old fault zone. It’s pretty wide. It goes from the Laurentians basically down to the U.S. border. And the fault formed when the Atlantic Ocean was opening, so hundreds of millions of years ago,” she said. “But faults in continents never fully heal. So it’s always this weak spot.”