It had been a typical day for Terri Vanderwerf as she sat at her desk at Orangeville Motors Wednesday afternoon.

“Suddenly, my chair started to shake,” she said. “I was asking what was going on when noticed that the modular panels in our office were shaking as well.

“I was scared.” Ms. Vanderwerf was one of millions who experienced the tremors of a magnitude 5.0 earthquake that hit southern Ontario, parts of Quebec and several U.S. States at about 1:45 p.m.

Hugh Sutherland, a retired geologist and geological engineer who lives on Second Line in Mono, offered up possible reasons for the tremor; dismissing any notion it was caused by all the England soccer fans jumping for joy after their team’s win over Slovenia at the World Cup.

“They would be more inclined to create a tornado with all their hot air,” quipped Mr. Sutherland.

In a more serious vein, he explained that the St. Lawrence Valley is part of a vertical fault where two geological structures abut against each other.

(This is opposed to the famous San Andreas fault in

California, which is a horizontal fault were two structures lie on top of each other).

The origins of Wednesday’s earthquake, Mr. Sutherland suggested, could be out at sea. “Activity on the subterrainian ocean floor are commonly the cause,” he said. Movements there push the structures up against each other and cause the tremors.

He was sitting at his computer on Wednesday when it started to jump all over his desk. Admitting that “this one today was as good as I’ve felt,” Mr. Sutherland also felt this was “a no-worry situation.”

Nevertheless, he pointed out that central Canada is not immune to earthquakes, even if they may not be as extreme as the one that recently devastated Haiti.

“The whole earth is under stress at all times,” said Mr. Sutherland. “There are pressures building up down there. Things could go bang tomorrow, or things could go bang 10,000 years from now.”

In 2005, a magnitude 4.2 earthquake hit an area suspected to have an epicentre about 45 kilometres from Owen Sound..

A Geological Survey of Canada seismologists said at the time that people in the area “probably got a good shake, but there wouldn’t be any damage associated with this, except for maybe a knickknack that might have fallen off a shelf.”