For nearly five minutes, a continent shuddered.

Good Friday: The Day Alaska Shook the World

The most powerful earthquake ever recorded in North America

The 1964 Good Friday earthquake (magnitude 9.2) devastated Alaska and sent tsunamis across the Pacific, reshaping our understanding of Earth's geology.

The ground began shaking at 5:36 PM on March 27, 1964 (Good Friday) and did not stop for nearly five minutes. The 1964 Alaskan earthquake — officially magnitude 9.2, the most powerful ever recorded in North America and the second most powerful in history — devastated southern Alaska and sent tsunamis racing across the Pacific Ocean.

In Anchorage, entire city blocks dropped twenty feet as the earth liquefied. The Turnagain Heights neighborhood, built on unstable bluff soil, slid into Cook Inlet, taking dozens of homes with it. In Valdez, the harbor collapsed into the bay, and a tsunami subsequently killed 32 people.

The tsunami caused destruction as far away as Oregon and California. In Crescent City, California, a series of waves killed 11 people and destroyed much of the downtown. The waves traveled 8,445 miles to Antarctica.

Yet despite its extraordinary power, the death toll was a relatively modest 131 people — because Alaska's population density was so low. The earthquake fundamentally changed how scientists understood the mechanics of megathrust earthquakes at subduction zones, leading to the development of plate tectonics theory as the dominant framework for understanding…

💡 The earthquake caused the ground in Houston, Texas to rise and fall by several inches — some 2,000 miles away.