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10 Amazing Facts About the 1964 Alaska Earthquake

Geologic shake-up

1964 alaska earthquake damage

An aerial view of the Turnagain Heights landslide in Anchorage. The area is now Earthquake Park. (Image credit: USGS)

The Great Alaska earthquake struck at 5:36 p.m. Alaska Standard Time on March 27, 1964. The shaking lasted for more than four minutes, launching several deadly tsunamis and triggering killer landslides. The earthquake also transformed geology, because it revealed that oceanic plates are shoved under continents. This was one of the keys that unlocked the theory of plate tectonics.

Deadly tidal waves

1964 alaska earthquake damage

Tsunami damage in Kodiak, Alaska (Image credit: USGS)

Of the 131 people killed during the earthquake, 119 died in tsunamis. Most were killed by tsunamis triggered by underwater landslides, not by the earthquake-induced tsunami.

Schoolhouse lives

1964 alaska earthquake damage

Tsunami damage in Chenega, Alaska (Image credit: USGS)

In Chenega, 25 of the village's 76 residents drowned in a tsunami. The only building that survived the wave intact was the schoolhouse, built 100 feet (30 meters) above sea level.

Deadly ground

1964 alaska earthquake damage

Tsunami damage in Valdez, Alaska (Image credit: USGS)

Several towns and villages were moved to safer ground after the tsunamis, including Seward, Valdez, Girdwood and Chenega.

Snapped trees

1964 alaska earthquake damage

Here, trees up to 101 feet (30 meters) above sea level were splintered by the tsunami generated by an underwater landslide in Port Valdez, Prince William Sound. (Image credit: USGS)

The tallest tsunami wave height was 219 feet (67 m) in Shoup Bay in the Valdez Inlet.

The day the earth moved

1964 alaska earthquake seismogram

A seismogram of the 1964 Alaska earthquake recorded in Namibia. (Image credit: IRIS)

The world rang like a bell for several weeks from the earthquake waves.

Sloshing and jostling

1964 alaska earthquake map

Map of the United States showing the occurrence of seiche waves after the 1964 Alaska earthquake. (Image credit: USGS)

Seiche waves, sloshing of water back and forth in a small body of water like a boat harbor or swimming pool, were noted as far away as Louisiana, where a number of fishing boats were sunk. Oscillations in the height of water in wells were reported as far away as South Africa.

Second-biggest earthquake

1964 alaska earthquake map

Map of Alaska showing the areas of uplift and subsidence following the 1964 earthquake. (Image credit: USGS)

The earthquake initially had a magnitude of 8.5 on the Richter scale. The moment magnitude scale, a better measure of seismic power, has since superseded the Richter scale. The new size estimate is magnitude 9.2, the second most powerful ever recorded.

Atomic force

1964 alaska earthquake damage

Oil tanks failed and caught fire after the earthquake. (Image credit: USGS)

If the energy of a magnitude-5 earthquake is like snapping a single spaghetti strand, then a magnitude-9.2 earthquake releases enough energy to snap 800,000 spaghetti strands, according to the U.S. Geological Survey.

Years of recovery

1964 alaska earthquake damage

It took 2.5 years to repair the earthquake damage to the Alaska Railroad. (Image credit: USGS)

The damage totaled about $300 million in 1964 dollars ($2.3 billion in 2013 dollars).

Seismic central

Earthquakes in Alaska

Earthquakes in Alaska (Image credit: USGS)

Four out of five earthquakes in the United States occur in Alaska. After the 1964 megathrust earthquake, three-quarters of the Aleutian subduction zone ruptured in a span of eight years. The subduction zone is 2,100 miles (3,300 kilometers) long.

Becky Oskin
Becky Oskin covers Earth science, climate change and space, as well as general science topics. Becky was a science reporter at Live Science and The Pasadena Star-News; she has freelanced for New Scientist and the American Institute of Physics. She earned a master's degree in geology from Caltech, a bachelor's degree from Washington State University, and a graduate certificate in science writing from the University of California, Santa Cruz.