點解British Columbia 會有咁多地震( 詳細+英文 唔該) 15分!

How often do earthquakes occur in western Canada?Every day! Scientists at the Geological Survey of Canada office near Sidney, B.C. record and locate approximately 1000 earthquakes each year in western Canada.

Why are there so many earthquakes in western Canada?
Western Canada is the most seismically active region in Canada. Most of the seismicity occurs in areas of fractured oceanic crust, which mark boundaries of small plates known as the Explorer and Juan de Fuca plates.
Earthquake activity is also high in the Cascadia Subduction Zone. Here, the Juan de Fuca Plate dips below the easterly neighbouring North American plate. Thus, both deep (dipping plate) and shallow (overriding plate) earthquakes occur in this zone, though no earthquakes occur at the interface of the plates.
The St. Elias Mountains, southwest Yukon Territory and the extreme northwest of B.C., too, is a highly seismic region. This is because of plate margin deformation between two converging plates in the area (the "Pacific" to the west and "North American" to the east.)
Finally, the Canadian Cordillera typically shows intense seismicity north of 60 degrees in a broad zone through the Mackenzie and Richardson Mountains.

圖片參考：http://earthquakescanada.nrcan.gc.ca/gen_info/images/can2005haz.jpg