Top 5 Powerful Earthquakes Ever Recorded in the US: Check Magnitude and Year

Earthquake in the US: The ground we walk on may seem stable, but the US is no stranger to the Earth's great power, which is why we often feel earthquakes. Some earthquakes have changed the way we think about geological forces and the way the land looks. These earthquakes have happened in places as far apart as Alaska's big, empty areas and California's busy cities. A 7.3 magnitude earthquake near Alaska on July 17, 2025, was a strong reminder of the "Ring of Fire," which runs along much of the US coastline. This shows how important it is to know about these natural events. Let's look at the five biggest earthquakes ever recorded in the US. We'll talk about how big they were and when they happened.

List of the Largest Earthquakes Ever in the US

This list shows the biggest earthquakes that have ever happened in the US, along with their size, location, and year. 

1. 1964 Prince William Sound, Alaska Earthquake 

On March 27, 1964, Alaska had the second biggest earthquake ever recorded in the world. The M9.2 "Good Friday Earthquake" shook Southcentral Alaska for more than four minutes, causing cracks in the ground, landslides, and a lot of damage to buildings. The tsunamis that came after the earthquake killed 139 people and destroyed towns and cities along the coast. They even reached California. Its great strength changed the land and taught us a lot about how to prepare for earthquakes.

Fourth Avenue in Anchorage, Alaska, after the earthquake

2. 1700 Cascadia Subduction Zone Earthquake 

People think that the megathrust earthquake that hit the Pacific Northwest coast (now Washington, Oregon, and California) on January 26, 1700, was a very strong M9.0. There are no written records from that time in North America, but geological evidence like "ghost forests" and accurate Japanese tsunami records show that it did happen. This big event made a huge tsunami that crossed the Pacific and hit shores that were very far away.

1700 Cascadia earthquake region

3. 1965 Rat Islands, Alaska Earthquake 

On February 4, 1965, an M8.7 earthquake struck the Rat Islands, which are far away in Alaska's Aleutian chain. This happened less than a year after the Great Alaska Earthquake. This powerful event caused a 35-foot tsunami on Shemya Island and was felt over a wide area of the Pacific. It was a big event, but it happened in a remote area with few people living there, so there wasn't much damage or loss of life. Most of the damage was to infrastructure.

1965 Rat Islands, Alaska Earthquake, courtesy - Haikudeck

4. 1946 Unimak Island, Aleutian Islands, Alaska Earthquake 

On April 1, 1946, an M8.6 earthquake off the coast of Unimak Island caused a huge tsunami that swept across the Pacific. People call it the "April Fools' Day Tsunami." The ground shaking caused some damage nearby, but the tsunami that came after it was over 100 feet high near the epicenter. It destroyed the Scotch Cap Lighthouse and killed all five people inside. The first US tsunami warning system was set up because its waves killed and destroyed a lot of things, especially in Hilo, Hawaii.

Unimak Island, Alaska, after the tsunami

5. 1957 Andreanof Islands, Alaska Earthquake 

On March 9, 1957, this M8.6 earthquake hit south of Alaska's Andreanof Islands. It caused a huge tsunami that hit Hawaii and the rest of the Pacific, but it wasn't as bad as the one in 1946 because the Seismic Sea Wave Warning System had gotten better, giving people more time to get ready. No one died, but Hawaii's property was badly damaged. This shows how important it is to have good early warning systems.

1957 Andreanof Islands after earthquake

When was the Last Major Earthquake Recorded in the US?

The 1964 Great Alaska Earthquake is still the biggest one ever recorded in the US, but there is still a lot of seismic activity. Most recently, on July 17, 2025, a 7.3 magnitude earthquake hit off the coast of Alaska, which led to tsunami warnings for coastal areas.

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Learning about the history of big earthquakes in the US helps us understand how the Earth is still changing our landscapes. These strong earthquakes, especially the ones that happen along the Pacific Ring of Fire, are important reminders that we need to keep getting ready and learning about them to lower the risks and keep people safe all over the country.