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Andy Wilson was immersed in his morning routine, shaving soap freshly slathered on his face, when the biggest earthquake in years shook the Queen Charlotte Islands yesterday and set his two-storey house swaying.

With the ceiling shaking, he rushed out to find his two oldest children - they weren't hurt, but his five-year-old son was cowering.

"My little guy was hiding under the blanket," said the 56-year-old teacher.

Upstairs, his wife, Janna, and the couple's one-year-old son felt the power of the earthquake even more intensely as the entire second storey rocked.

The earthquake and the three aftershocks that rumbled through the Queen Charlotte Islands, starting at 7:30 local time, were more notable for such fleeting moments of fright than any destruction.

Local officials said there was no significant damage from the magnitude 6.5 earthquake, in part because the island communities have low-slung sturdy buildings.

The genesis of the earthquake was also a major factor in limiting any damage. Although the quake's epicentre was relatively close to land, it was what seismologists call a strike-slip - a horizontal grinding of tectonic plates, akin to a car sideswiping an oncoming vehicle.

Such a seismic event is not the kind likely to generate a tsunami, said Stéphane Mazzotti, a seismologist with the Geological Survey of Canada.

Earthquakes Canada's website said the quake happened just off the southern tip of the Queen Charlotte Islands, often referred to as the Haida Gwaii, and 160 kilometres south from the village of Queen Charlotte.

The earthquake started near, but not on, the Queen Charlotte Fault - which Earthquakes Canada describes as the Canadian equivalent of the San Andreas Fault.

Within an hour of the initial quake, Carol Kulesha, mayor of the village of Queen Charlotte, said provincial emergency officials informed her that there was no tsunami danger.

Mr. Mazzotti said there was an earthquake of similar magnitude near the Queen Charlotte Islands in January, 2008, but its epicentre was further away from the islands, so humans didn't feel its effects so keenly.

By contrast, there were reports of yesterday's quake from as far away as Smithers, about 400 kilometres to the east in the interior of British Columbia, according to Mr. Mazzotti.

Ms. Kulesha said the initial earthquake was strong enough to wake her up. "It was significant enough to make me feel I was in a train," said the mayor, who has lived in the Queen Charlottes since 1970.

Earthquakes are a fact of life on Canada's West Coast, including on the chain of islands that make up the Queen Charlottes, which sit along the Pacific Ring of Fire. Most of those earthquakes go unnoticed by most people, either because they are too small or too distant.

A seismic event the size of yesterday's earthquake could be expected every year or two, Mr. Mazzotti said. What made this one more notable is that it was close enough to rattle humans.

Geologist John Clague said British Columbia was fortunate that such an earthquake didn't happen near a populated and built-up area such as Vancouver.

That would have caused tens of billions of dollars in damage, said Mr. Clague, director of Simon Fraser University's Centre for Natural Hazard Research.

And yesterday's earthquake is a distant contender to the biggest in recent Canadian history, which also hit the Queen Charlottes.

That quake (the most powerful since 1700) struck on Aug. 22, 1949, and was a magnitude 8.1. According to Earthquakes Canada, the resulting tremors toppled chimneys, shattered windows - and knocked cows to the ground.

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B.C. quake

Earthquakes such as the one off the Queen Charlotte Islands on Tuesday occasionally occur as tectonic plates collide.

Canada's West Coast is part of an area of frequent earthquakes called The Ring of Fire

Strike-slip Occurs when tectonic plates move and grind past each other horizontally

The quake measuring 6.5 on the Richter scale was recorded at 7:30 a.m. (PT) on Tuesday. It was followed by three smaller aftershocks

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THE RICHTER SCALE

Scale / Quakes per year / Typical effects

Less than 3.4: 800,000 - Detected only by seismometers

3.5 - 4.2: 30,000 - Just about noticeable indoors

4.3 - 4.8: 4,800 - Most people notice them, windows rattle

4.9 - 5.4: 1,400 - Everyone notices them, dishes may break, open doors swing

5.5 - 6.1: 500 - Slight damage to buildings, plaster cracks, bricks fall

6.2 - 6.9: 100 - Much damage to buildings, chimneys fall, houses move on foundations

7.0 - 7.3: 15 - Serious damage, bridges twist, walls fracture, buildings may collapse

7.4 - 7.9: 4 - Great damage, most buildings collapse

More than 8.0 - One every 5-10 years - Total damage, surface waves seen, objects thrown in the air

NINIAN CARTER/THE GLOBE AND MAIL / SOURCES: NATURAL RESOURCES CANADA; U.S. GEOLOGICAL SURVEY; UNIVERSITY OFLIVERPOOL

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