When most Americans think of earthquake risk, they think of California. But significant seismic hazard exists across much of the country, including the New Madrid Seismic Zone (Missouri/Tennessee), the Pacific Northwest's Cascadia Subduction Zone, and parts of Alaska, Hawaii, and Oklahoma.
California's Fault Lines
The San Andreas Fault system remains the most well-known earthquake hazard in the US. The USGS estimates a 72% probability of a magnitude 6.7+ earthquake in the San Francisco Bay Area within 30 years. Los Angeles faces similar probabilities along the San Andreas and related faults.
The Cascadia Threat
The Cascadia Subduction Zone off the coast of Oregon and Washington is capable of producing magnitude 9.0+ earthquakes and devastating tsunamis. The last major Cascadia event was in 1700. Geologists estimate a 10-14% probability of a major event within 50 years.
Induced Seismicity
Oklahoma has experienced a dramatic increase in earthquakes linked to oil and gas wastewater injection. While these are typically smaller than tectonic earthquakes, they've caused structural damage and raised insurance costs across central Oklahoma ZIP codes.