The strongest quake in North American history. It shook for four and a half minutes and lifted one island's shoreline eleven metres into the air, stranding barnacles that still mark the old sea line.
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DownloadThe 1964 Great Alaska earthquake, at magnitude 9.2, is the most powerful earthquake ever recorded in North America and the second-largest ever measured worldwide. It ruptured the megathrust where the Pacific plate dives beneath North America, and the ground shook for around four and a half minutes.
The shaking set off enormous submarine and coastal landslides, and the tsunamis they generated — together with the main tectonic tsunami — caused most of the deaths, striking communities across coastal Alaska and reaching as far south as California and Oregon.
The disaster helped cement the young theory of plate tectonics: mapping how the land permanently rose and dropped across the region gave scientists some of the clearest early evidence for subduction.