Possible industry-related earthquake jolts northern Alberta Saturday night

Some residents of northwestern Alberta reported feeling an earthquake that was recorded in the region on Saturday night.

Earthquakes Canada said the quake had a preliminary magnitude of 4.2, about 36 kilometres south of the city of Grande Prairie, Alta.

The quake is possibly an industry-related event, Earthquakes Canada said.

Taimi Mulder, an earthquake seismologist with Natural Resources Canada at the Pacific Geoscience Centre in Sidney, B.C., said the earthquake was reported at 9:13 p.m.

About 70,000 people live in Grande Prairie, located about 460 kilometres northwest of Edmonton.

"There was one report from someone quite close to the epicentre of the earthquake. They felt two sharp jolts," Mulder told CBC News in an interview Sunday.

"Most people in the Grande Prairie area felt it very lightly."

No damage was reported.

"Usually damage starts at around magnitude 5.0 and 5.5, depending on how close you are to the event and how well designed the building was, but our building code is very good and for buildings built after 1985. I would not expect to see damage," Mulder said.

Mulder said the earthquake was in a region that has previously seen industry-related events, including two in February. 

A 4.7 magnitude earthquake was reported Feb. 20, about 60 kilometres south of Grande Prairie. It was lightly felt in the region including Edson, Jasper, Hinton and Edmonton. A 4.0 magnitude quake was reported in the same area earlier that same day.

The Alberta Energy Regulator said in a statement that it is aware of the earthquake which they estimate as a 4.04 magnitude event. 

The Alberta Geological Survey, a branch of the regulator, is reviewing data from this incident to determine the cause, AER's statement said.

"Scientists at the AGS use more than 70 monitoring systems to measure and research seismic activity across Alberta," AER said. 

"The AGS utilizes this information to form an accurate picture of earthquake locations, magnitudes and discern the nature of these events."

Earthquakes Canada's magnitude scale shows that quakes between 3.5 and 5.4 are "often felt, but rarely cause damage."