VANCOUVER - A booming gas extraction process that has environmentalists all shaken up is being probed by two different studies to determine if it's also causing the depths of Canada to rattle and roll.
The research into whether hydraulic fracturing, or fracking, can trigger earthquakes is being conducted just as a pair of independent papers were released internationally this week suggesting they do.
The studies out of mid-continent U.S. and Britain found that shallow, man-made tremors may be linked to the blasting of water, sand and chemicals deep underground to break open rock to obtain crude oil and natural gas.
Experts and critics alike are waiting for conclusive results from home soil before suggesting industry practices should be altered.
"These are tiny earthquakes and they're the variety that occur thousands of times a day around the world," said John Cassidy, a federal government seismologist in Victoria, B.C., of the international findings.
He said mounting interest and unusual vibrations in British Columbia have prompted closer study at home.
"The idea is to be able to provide well-grounded science advice that can be used by regulators across the country for their decision-making."
A four-year study was launched by the federal Natural Resources Department on April 1. With the aid of industry regulators and universities, it will seek to unearth whether fracking has inducing quakes in British Columbia, New Brunswick and Quebec, Cassidy said.
A provincial study is also underway in a region of northeastern B.C. called the Horn River Basin, where at least 11 energy companies are developing significant shale gas extraction projects. The study, being conducted by the BC Oil and Gas Commission with commercial co-operation, should be completed later this year.
"They've seen some seismic activity in that area ... (It's) definitely worth taking a look at," said Travis Davies, a spokesman for the Alberta-based Canadian Association of Petroleum Producers, which represents 90 per cent of the Canadian industry.
"If you want to have a licence to operate and be on the land, you need to have public support. The public needs to feel safe and comfortable and that's why we support the (commission's) work."
The province's west coast already experiences about 2,000 natural quakes annually, Cassidy said.
Yet 36 earthquakes have occurred in the otherwise seismically quiet region near Fort Nelson over the past three years. Most hovered between magnitude two and three in scale, a class considered minor but that could be felt as shaking by someone in the close vicinity.
Fracking in that region occurs about 2.5 kilometres under ground, around the same depth the natural tremors occur. Drinking water wells are situated about 150 metres to 300 metres in depth.
B.C. Energy and Mines Minister Rich Coleman said Tuesday the implications of the recent studies will be considered within the province's own examination.
"This study will help ensure B.C. remains a leader in safe and responsible natural gas activities," he said in a statement.
A spokesman for the BC Oil and Gas Commission referred a request for comment back to the minister.
Two further reviews of the environmental impact of fracking were announced in September by federal Environment Minister Peter Kent. The ministry will conduct one assessment, while an independent panel has been tasked with the other.
On Wednesday, the U.S. Geological Survey was set to release at a conference in San Diego its own findings that a "remarkable" increase of quakes in middle U.S. since 2001 is "almost certainly" the result of oil and gas production.
The study says there's been a six-fold increase in seismic events there over 20th century levels, and it appears to be related to deep, waste-water injection wells.
"A naturally-occurring rate change of this magnitude is unprecedented outside of volcanic settings or in the absence of a main shock, of which there were neither in this region," the study abstract says.
Its authors note that work remains to determine how the quakes are related to methods of extraction or the rate of gas production.
Experts in the U.K. have interpreted another study, released on Monday, as showing that so long as regulations are effectively implemented, the risk of induced quakes should not prevent further hydraulic fracturing.
"They are of insufficient magnitude and extent to cause structural damage or to allow gas or chemicals to leak into much shallower drinking water aquifers," geosciences Prof. Andrew Aplin, of Newcastle University, said in a statement.
The study, released by the British Geological Survey and commissioned by a resources company, focused on a particular shale gas fracturing operation in northwest England after a series of quakes there one year ago. It found they occurred after fluid was injected into a nearby fault zone.
Fracking is well established in B.C., Alberta and Saskatchewan, and exploration is picking up pace in almost every other province.
Opposition has also ramped up steadily since the release of the 2010 Josh Fox documentary "Gasland," which shows residents of small-town Colorado setting alight tap water they charge was soured by local fracking.
Ben Parfitt, who has researched fracking for two years at the Canadian Centre for Policy Alternatives, said concerns and questions arise from the notion of manmade earthquakes.
"Generally speaking, the way in which fracking operations are presented to the public ... is that these are highly-controlled operations," he said. "If you're inducing small earthquakes underground, how able are you to determine what the outcome is?"
He fears the possibility of ground-water contamination or gas migration that could put public health and safety at risk.
A 1994 study in the Fort St. John area of B.C., prompted by several small earthquakes in the preceding decade, showed that reducing injection pressure when fracking could stem the tremors, Cassidy said.
"It was a study that benefited the community, because it was understood what caused these small earthquakes ... and it benefited industry because they could do their work without causing these earthquakes," he said. "It was a good win-win situation."