A large earthquake, magnitude 6.7, has occurred off the west coast of Vancouver Island.The West Coast Alaska Tsunami Warning Centre has advised that no areas of coastal BC are at risk from the quake.The earthquake happened at 12:41 pm Friday afternoon, and there are reports that it was felt in Vancouver.There have been a dozen or more aftershocks since the earthquake, the largest 4.9 magnitude. Earthquake officials say they expect the largest aftershock likely following a quake of this magnitude would be about 5.This type of earthquake occurs about every 10 years off Vancouver Island.