The swarms of small earthquakes of the B.C. coast are an indication of the constantly shifting plates beneath the Pacific that are building up tremendous energy. (CBC)

The moderate earthquakes off the Queen Charlotte Islands Tuesday have many people once again wondering when the "big one" will hit the West Coast.

New research shows that a major quake — expected anytime in the next 200 years — could be much more devastating than previously thought.

It has been assumed for decades that the point where colliding tectonic plates would release tremendous earthquake-generating energy was about 145 kilometres off the coast of B.C. and Washington state.

But U.S. researchers using a specialized GPS system to monitor plate movement have found that the release point will be much closer to the mainland, coming within about 80 kilometres of major cities.

Release point 45 per cent closer to cities

"The edge of where the fault will actually rupture to [is] about 65 kilometres closer than is [generally] assumed," Tim Melbourne, a professor of Geophysics at Central Washington University told CBC News.

"[It] matters in this context because of all the big cities [nearby] — Seattle, Portland, Bellingham, Olympia, Vancouver, Canada."

"The physics is not any different than a firecracker," said Melbourne. "Think of a firecracker set off across a field from you versus a firecracker set off five metres from your ear."

Melbourne said an earthquake measuring about 9.0 — close to the magnitude of the quake that devastated Sumatra and created the massive tsunami five years ago — will eventually hit the region.

Major quakes are believed to occur there every 500 to 600 years and the last one struck in the year 1700.