WThe 1700 Cascadia earthquake occurred along the Cascadia subduction zone on January 26 with an estimated moment magnitude of 8.7–9.2. The megathrust earthquake involved the Juan de Fuca Plate from mid-Vancouver Island, south along the Pacific Northwest coast as far as northern California. The length of the fault rupture was about 1,000 kilometers, with an average slip of 20 meters (66 ft).
WThe 1918 Vancouver Island earthquake occurred in British Columbia, Canada at 12:41 a.m. Pacific Standard Time on December 6. The earthquake was most likely of the strike-slip type, and was estimated to have a maximum perceived intensity of VII on the Mercalli intensity scale. The epicenter was located east of the Stewardson inlet on the west coast of Vancouver Island, with damage occurring at the Estevan Point lighthouse on the Hesquiat Peninsula. The event registered 7.2 on the moment magnitude scale and was felt as far as northern Washington state and the interior of British Columbia.
WThe 1946 Vancouver Island earthquake struck Vancouver Island on the Coast of British Columbia, Canada, on June 23 at 10:15 a.m. with a magnitude estimated at 7.0 Ms and 7.5 Mw. The main shock epicenter occurred in the Forbidden Plateau area northwest of Courtenay. While most of the large earthquakes in the Vancouver area occur at tectonic plate boundaries, the 1946 Vancouver Island earthquake was a crustal event. Shaking was felt from Portland, Oregon to Prince Rupert, British Columbia. This is one of the most damaging earthquakes in the history of British Columbia, but damage was restricted because there were no heavily populated areas near the epicentre, where severe shaking occurred.
WThe 1949 Queen Charlotte Islands earthquake struck the sparsely populated Queen Charlotte Islands and the Pacific Northwest coast at 8:01 p.m. PDT on August 21. The shock had a surface wave magnitude of 8.1 and a maximum Mercalli Intensity of VIII (Severe).
WThe 1964 Alaskan earthquake, also known as the Great Alaskan earthquake and Good Friday earthquake, occurred at 5:36 PM AKST on Good Friday, March 27. Across south-central Alaska, ground fissures, collapsing structures, and tsunamis resulting from the earthquake caused about 131 deaths.
WThe 2007–2008 Nazko earthquakes were a series of small volcanic earthquakes measuring less than 4.0 on the Richter magnitude scale. They took place in the sparsely populated Nazko area of the Central Interior of British Columbia, Canada starting on October 9, 2007 and ending on June 12, 2008. They occurred just west of Nazko Cone, a small tree-covered cinder cone that last erupted about 7,200 years ago.
WThe 2012 Haida Gwaii earthquake occurred just after 8:04 p.m. PDT on October 27. The shock had a moment magnitude of 7.8 and a maximum Mercalli Intensity of VIII (Severe). The earthquake's epicentre was on Moresby Island of the Haida Gwaii archipelago. This was the second largest Canadian earthquake ever recorded by a seismometer, after the 1949 Queen Charlotte Islands earthquake, about 135 kilometres (84 mi) away.
WThe Cascadia subduction zone is a convergent plate boundary that stretches from northern Vancouver Island in Canada to Northern California in the United States. It is a very long, sloping subduction zone where the Explorer, Juan de Fuca and Gorda plates move to the east and slide below the much larger mostly continental North American Plate. The zone varies in width and lies offshore beginning near Cape Mendocino, Northern California, passing through Oregon and Washington, and terminating at about Vancouver Island in British Columbia.