Hi Petra. There is an average of one earthquake in southwest B.C. every day. Nearly all are too small to be felt, but a damaging earthquake occurs somewhere in the region about once every 20 years. The largest earthquake in this century was a magnitude 7.3 event in 1946, centered beneath central Vancouver Island. Were this earthquake to occur today under Vancouver, damage would be in the billions of dollars. Recently, scientists have recognized a history of infrequent, but great (magnitude 8 to 9) earthquakes on the fault separating the subducting Juan de Fuca and North America plates. The last great earthquake in 1700 AD affected the entire coast from northern California to southern B.C.

The effect of an earthquake includes ground shaking, landslides, and liquefaction (change of sediment from a solid to a quicksand-like liquid state). Earthquakes are most destructive when they are centered near cities, but the damage can differ considerably from site to site because of local geological conditions. For example, shaking on loose sediment is likely to be greater than shaking on bedrock. Some earthquakes trigger destructive sea waves (tsunamis) that can surge hundreds of metres inland, have heights of 10 m or more, and cause loss of life and severe property damage. In southwest B.C., the tsunami threat is greatest on the outer coast of Vancouver Island.

Earthquakes Felt In Vancouver

1700 AD west of Vancouver Island magnitude 8+ (great earthquake; native villages destroyed)
Dec. 15, 1872 north-central Washington magnitude 7.4 (felt strongly on the Lower Mainland)
Jan. 11, 1909 San Juan Islands magnitude 6 (felt strongly in Lower Mainland)
Dec. 6, 1918 Vancouver Island. magnitude 7 (damage on west coast of Vancouver Isl.)
Jan. 24, 1920 San Juan Islands, magnitude 5.5 (felt strongly in the Lower Mainland)
June 23, 1946 Vancouver Island, magnitude 7.3 (much damage on central Vancouver Isl.)
April 13, 1949 Puget Lowland, magnitude 7 (much damage in Seattle and Tacoma)
April 29, 1965 Puget Lowland, magnitude 6.5 (much damage in Seattle)
Nov. 30, 1975 Strait of Georgia magnitude 4.9 (many aftershocks)
May 16, 1976 southern Gulf Islands magnitude 5.4
April 14, 1990 Fraser Lowland magnitude 4.9 (many aftershocks)
May 3, 1996 east of Seattle magnitude 5.5 (felt in the Lower Mainland) Take Care...Don in creepy town