Tremors can last months: Study sheds light on Alberta’s fracking earthquakes
CALGARY — Research suggests hydraulic fracking can cause earthquakes in at least two ways — and one of them can cause tremors months after the activity stops.
“The seismicity is persistent after the operations are completed,” said David Eaton, a University of Calgary seismologist, whose paper has been published in the journal Science.
Eaton has been studying earthquakes that have shaken the Fox Creek region of northwestern Alberta for years.
The largest, measuring between 4.2 and 4.8 on the Richter scale, occurred in January. The area, which is in the centre of the Duvernay oil and gas field, has experienced hundreds of tremors since 2013.