Early historical and ethnographical accounts of large earthquakes and tsunamis on western Vancouver Island, British Columbia

Abstract

Abundant geological evidence has been found for one or more large earthquakes on the Cascadia subduction zone about 300 years ago. The earthquakes produced severe shaking, crustal subsidence, and large tsunamis along the Pacific coast from Vancouver Island to northern California and must have profoundly affected the people living in these areas. Northwest Coast Indian oral traditions record, albeit in an exaggerated way, tsunamis triggered by these rare, plate-boundary events. The oldest known historical earthquake in British Columbia, in February 1793, was recorded by Spanish explorers wintering at Nootka Sound on Vancouver Island and may have occurred at shallow depth in the crust or deeper, within the subducting Juan de Fuca plate.