A leading seismic scientist says B.C.'s energy infrastructure and gasfield workers may be vulnerable to earthquakes caused by fracking.

Earthquakes triggered by fracking have been felt in Fort Nelson and Fort St. John, but University of Calgary geophysicist David Eaton says the shaking is strongest in remote areas near fracking sites.

"Certainly in the immediate area where there's infrastructure established by the oil and gas industry, including pipelines and well bore casings, then it's something that really requires some careful analysis," said Eaton.

Fracking, the common name for hydraulic fracturing, is the process of injecting water, sand and chemicals at high pressure deep underground to break rock and free gas.

New research shows fracking-induced quakes are shallow, so they trigger stronger ground motion and shaking — potentially damaging in places without much earthquake preparedness.

Eaton, part of a national research network looking into "induced seismicity" — earthquakes caused by fracking — in northern B.C. and Alberta, says energy regulators are taking the issue "very seriously."

The quakes are hitting far from cities and towns, he said, but pipelines, gas wells and workers at fracking sites are all vulnerable.

"If people are being shaken up by ground motions, then it makes it a matter of public concern," he said.

WorkSafeBC spokeswoman Trish Knight Chernecki said she's not aware of any workplace injuries caused by seismic activity.

"Our officers in the northeast of B.C. continue to inspect oil and gas workplaces and hold employers accountable for the health and safety of their workers including maintaining the safety of industry infrastructure," she said.

Fracking triggered 2014 quake

Eaton's concerns come amid the news that fracking triggered a 4.4-magnitude earthquake in northeastern B.C. last year, one of world's largest earthquakes ever linked to the controversial process.

The 4.4-magnitude quake was felt in Fort St. John and Fort Nelson in August 2014. It was preceded by a 3.8-magnitude earthquake in late July, also caused by fracking.

In January, Alberta's energy regulator reported fracking likely caused a 4.4-magnitude earthquake in the northern town of Fox Creek.

Meanwhile, B.C.'s Oil and Gas Commission continues to investigate whether a 4.6-magnitude quake only three kilometres from a fracking site was triggered by hydraulic fracturing this month.

Why is Canada different?

Eaton said the fracking-related earthquakes seen in Canada are different from those felt in the U.S.. In the U.S., larger earthquakes have been triggered — but they're due to disposal of fracking wastewater, not fracking itself.

"Of all the induced earthquakes that are directly related to hydraulic fracturing, the ones we're seeing in Western Canada are certainly at the top," said Eaton.

"Worldwide [these quakes are] the highest magnitude events that are attributed to hydraulic fracturing anywhere in the world."

Research is ongoing into why such large quakes are being triggered in Canada by fracking alone.

"It's much different in Western Canada than in Oklahoma and Kansas — why is it different? That's the topic of intensive research. It's too early to say right now."