One of the strongest earthquakes in the history of Canada's Alberta was likely caused by the underground disposal of wastewater by the oil industry, researchers at Stanford University and University of Alberta suggested in a study.
The new findings contradict a preliminary statement from the Alberta Energy Regulator that said the earthquake was a natural event.
"We are aware of the study, and we are continuing to investigate these events ... due to the nature of seismic monitoring, any information should be considered preliminary until the investigation is complete," the Alberta Energy Regulator said in an emailed statement.
