The Largest Earthquakes in U.S. History

By Quake Tracker Live Editorial · Published November 9, 2026

The United States has experienced some of the largest earthquakes ever recorded anywhere on Earth. Most of them struck Alaska, where the Pacific plate dives beneath North America along the Aleutian Trench, but California, Hawaii, the central Mississippi Valley and the Pacific Northwest have all produced major events. The dates and magnitudes in this guide come from the U.S. Geological Survey (USGS) earthquake catalog, which we checked directly. Magnitudes of older events are modern reassessments and can be revised.

The largest earthquakes in U.S. history

The table lists the eight largest earthquakes in the USGS catalog whose epicenters were in Alaska or its offshore waters; every earthquake of magnitude 8 or higher on U.S. soil falls in that region. All magnitudes are moment magnitude (Mw).

The pattern is striking: every entry is in Alaska. The state sits on one of the most active plate boundaries on Earth, and it experiences a magnitude 7 earthquake roughly once a year on average, according to the USGS. Because most of these quakes occur offshore or in sparsely populated areas, they cause far fewer deaths than their size suggests.

The 1964 Good Friday earthquake

The magnitude 9.2 earthquake on March 28, 1964 remains the largest in U.S. history and the second largest ever instrumentally recorded worldwide, behind Chile in 1960. A fault segment hundreds of kilometers long slipped beneath Prince William Sound, and the ground shook for about four minutes. Parts of the coast sank or rose by several meters.

The shaking damaged Anchorage, but most of the roughly 130 deaths were caused by tsunamis, which struck Alaskan coastal towns and also traveled down the Pacific coast, causing deaths and damage in Oregon and California. The disaster led to major advances in earthquake science. It was key evidence for the theory of plate tectonics, and it prompted the creation of tsunami warning centers in the Pacific.

Beyond Alaska: the big ones in the other states

San Francisco, 1906

The 1906 earthquake ruptured the northern San Andreas Fault for roughly 480 km. The shaking was destructive, but most of the destruction in San Francisco came from fires that burned for days after water mains broke. The event gave rise to the elastic rebound theory, which is still the basis for understanding how earthquakes work: the ground builds up strain, and a fault releases it suddenly.

New Madrid, 1811-1812

Between December 1811 and February 1812, a series of at least three very large earthquakes, along with thousands of aftershocks, struck the New Madrid Seismic Zone near the Mississippi River. Because the rocks in the central United States are old, cold and well connected, the shaking carried far further than in California. Reports describe church bells ringing in Boston. A similar event today would affect cities such as Memphis and St. Louis, which is why the region is considered a significant hazard even though large quakes there are rare.

Cascadia, 1700

The Cascadia Subduction Zone runs offshore from northern California to Vancouver Island. Its last full rupture is dated to the evening of January 26, 1700, based on "ghost forests" of cedar trees killed by sudden subsidence and on detailed tsunami records in Japan, where a wave arrived with no local earthquake. Scientists estimate the earthquake at around magnitude 9. The USGS and state agencies treat a repeat as one of the greatest natural hazards in the Pacific Northwest. Read more in our guide to U.S. earthquake zones.

Recent notable earthquakes

• M7.1, Ridgecrest, California (July 6, 2019): the strongest California earthquake in two decades. It followed a M6.4 foreshock on July 4 by about 34 hours, and produced thousands of aftershocks. See our guide to aftershocks.
• M7.1, Anchorage, Alaska (November 30, 2018): an earthquake about 47 km deep beneath the Cook Inlet area caused significant damage to roads and buildings in the Anchorage area. Deep, intraslab events like this one are an important part of Alaska's hazard.
• M6.9, Kilauea, Hawaii (May 4, 2018): accompanied the 2018 eruption and was the strongest Hawaiian earthquake since 1975.
• M6.8, Nisqually, Washington (February 28, 2001): about 52 km deep beneath Puget Sound, it damaged buildings in Seattle and Olympia.
• M6.7, Northridge, California (January 17, 1994): among the costliest natural disasters in U.S. history, caused by a blind thrust fault under the San Fernando Valley.
• M6.9, Loma Prieta, California (October 18, 1989): damaged the Bay Bridge and the Cypress Structure freeway in Oakland.
• M5.8, Pawnee, Oklahoma (September 3, 2016): the largest earthquake recorded in Oklahoma, linked by scientists to wastewater disposal from oil and gas operations.

What the list tells us

• The biggest U.S. earthquakes happen where plates collide (subduction zones in Alaska and Cascadia) rather than at the strike-slip San Andreas Fault, which is capable of M7 to M8 but not M9.
• Size and damage are not the same thing. The M9.2 in 1964 killed roughly 130 people, while smaller earthquakes near large populations have caused much more harm. See our guide to magnitude.
• Instrumental records only reach back about a century. Geologic evidence, such as the buried marshes of the Pacific Northwest, shows that even larger earthquakes have occurred in prehistory.

To see how active your own state is right now, check the zone pages for Alaska, California and Hawaii, or the list of the biggest recent earthquakes.

Frequently asked questions

Sources and further reading

• USGS: Largest earthquakes in the United States
• USGS Earthquake Catalog search
• USGS: New Madrid seismic zone

This guide is general information, not professional or emergency advice. Quake Tracker Live is not an official warning system; follow instructions from local authorities.