Read this story from the Calgary Herald on the Oil and Gas Commission’s investigation into whether or not natural gas hydraulic fracturing operations are causing earthquakes in Northeast BC.

“Since 2009, there have been 31 earthquakes in the Horn River Basin,
an active natural gas extraction area. Before 2009, the area had not
experienced any recorded earthquake activity, said Friedrich. The
earthquakes ranged in size from 2.5 to 3.5 on the Richter scale, which
typically means they can be felt but rarely cause damage. Three of the earthquakes took place as hydraulic fracturing was underway, said Friedrich.” (Sept 30, 2011)

http://www.calgaryherald.com/news/Controversial+fracking+linked+earthquakes/5481341/story.html