1946 Vancouver Island earthquake
The 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 and 7.5 . 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. This earthquake is Canada's largest historic onshore earthquake. However, the greatest earthquake in Canadian history recorded by seismometers was the 1949 Queen Charlotte earthquake, an interplate earthquake that occurred on the ocean bottom just off the rugged coast of Graham Island, which reached magnitude 8.1 on the moment magnitude scale. Background and tectonics The tectonics that caused the 1946 Vancouver Island earthquake are poorly known. No surface expression of the offset was noticed, most likely because the epicenter area is very remote and densely forested. A comprehensive examination and computer