Today marks the anniversary of the 1964 Great Alaskan “Good Friday” earthquake and tsunami, a destructive and lethal natural disaster which first impact south-central Alaska but claimed lives and buildings far away across the Pacific. At 5:36 pm local time on Friday, March 27, the magnitude 9.2 megathrust earthquake lasted an almost unfathomable four minutes and thirty eight seconds. Rated as the most powerful earthquake in North American history and one of the most powerful recorded in modern times in the world, the event had more than 600 miles of fault rupture at once, moving up at 60 feet, releasing about 500 years of stress build-up.
The massive energy released from the earthquake led to soil liquefaction, fissures, landslides, and other ground failures which led to significant structural damage and great loss of personal property. Anchorage, Alaska saw the most destruction as roads and stores collapsed, with some portions of the city dropped down by the land movement brought about by the quake. While portions of Anchorage collapsed, portions of Kodiak dramatically rose upwards of 30 feet. Meanwhile, southeast of Anchorage near the Trunagain Arm near Girdwood and Portage, the land dropped as much as 8 feet.
The earth movement created a massive underwater landslide at Port Valdez in Prince William Sound. In addition to collapsing docks and smashing ships, the sudden underwater movement of land triggered a tsunami, sweeping many people out to sea. Numerous tectonic tsunamis and local tsunamis were generated by the violent earthquake action, with tsunami observed as far away as Peru, New Zealand, Hawaii, Japan, and Mexico. The largest tsunami wave was measured on the coast of Alaska with a height of about 220 feet. Tsunami claimed lives across the Pacific, with 12 people killed near Crescent City, California and 4 killed at Beverly Beach State Park on the Oregon coast.
The event created about $3 billion in damages (in 2023 dollars) and claimed 129 lives.
According to USGS, the earthquake rupture started approximately 15 miles beneath the surface, with its epicenter 6 miles west of Valdez and 75 miles east of Anchorage. The earthquake was felt throughout most of mainland Alaska, as far west as Dutch Harbor in the Aleutian Islands some 480 miles away, and at Seattle, Washington, more than 1,200 miles to the southeast of the fault rupture, where the Space Needle swayed perceptibly. The earthquake caused rivers, lakes, and other waterways to slosh as far away as the coasts of Texas and Louisiana. Water-level recorders in 47 states—the entire Nation except for Connecticut, Delaware, and Rhode Island— registered the earthquake.