Scientists have estimated that there have been at least 13 significant earthquakes along the Cascadia subduction zone in the past 6,000 years . The most recent , the 1700 Cascadia earthquake , was recorded in the oral traditions of the First Nations people on Vancouver Island . It caused considerable tremors and a massive tsunami that traveled across the Pacific Ocean . The significant shaking associated with this earthquake demolished houses of the Cowichan Tribes on Vancouver Island and caused several landslides . Shaking due to this earthquake made it too difficult for the Cowichan people to stand , and the tremors were so lengthy that they were sickened . The tsunami created by the earthquake ultimately devastated a winter village at Pachena Bay , killing all the people that lived there . The 1700 Cascadia earthquake caused near-shore subsidence , submerging marshes and forests on the coast that were later buried under more recent debris
1700 Cascadia earthquake
1700 Cascadia earthquake
Garibaldi Volcanic Belt