The British Columbia Energy Regulator is toughening its oversight of 鈥渋nduced鈥� seismic activity after a series of earthquakes linked to hydraulic fracturing, or fracking, in the northeastern corner of the province.
John Cassidy, a seismologist with Natural Resources Canada, says the regulator has confirmed that four quakes between last Saturday and Wednesday were related to the gas industry practice.
The quakes ranged in magnitude from 3.1 to 4.7, with the most powerful felt in Fort St. John, B.C., about 105 kilometres southeast of the epicentre.
Cassidy says earthquakes triggered by fracking in B.C. typically result from the injection of material into shallow wells to open up fractures and release gas for extraction, and almost all of the induced quakes are 鈥渢iny.鈥�
Still, the recent series of earthquakes were followed by an announcement from the energy regulator to strengthen oversight on Thursday by 鈥渆nhancing鈥� an existing order and adding a new one.
The orders both require operators in the area to immediately halt operations if they trigger a seismic event of a certain magnitude.
A shutdown would be triggered by a quake of magnitude 3 or higher within five kilometres of operations in the existing Kiskatinaw seismic monitoring and mitigation area.
The threshold is magnitude 4 in the nearby Wonowon-Pink Mountain area where a new order has been established.
Cassidy says that over the last year, there have been five quakes in the range of magnitude 4 within 100 kilometres of the most recent series, as well as 29 quakes of a magnitude of 3 to 3.9 and 74 with a magnitude of 2 to 2.9.
Magnitude 3 is typically when an earthquake may start to be felt, he adds, depending on proximity to the epicentre.
People living on southern Vancouver Island reported feeling a 3.8 magnitude earthquake that struck off the coast at around 10 p.m. Thursday.
It was lightly felt in Victoria, Sidney and across southern Vancouver Island, with Earthquakes Canada saying more than 300 people reported feeling it.
There was no reported damage from any of the recent quakes in B.C.
