Forget the San Andreas—two lesser-known U.S. zones may be due for a major quake.
When Americans think “earthquake,” they picture California’s infamous San Andreas Fault. But experts now warn that the next major seismic disaster may strike far from the Golden State. Two unexpected regions—the Pacific Northwest’s Cascadia Subduction Zone and the central U.S.’s New Madrid Seismic Zone—are flashing red on geologists’ radar. Alaska, too, continues to rumble with powerful quakes, shaking confidence that only the West Coast needs to worry.
These areas are experiencing increased seismic activity, updated hazard assessments, and renewed emergency planning. And if history is any guide, the next “Big One” may catch millions off-guard. Here are eight urgent reasons why California isn’t the only place you should be watching.
1. The Cascadia Subduction Zone could unleash a quake worse than anything California has ever seen.
Stretching from northern California to British Columbia, the Cascadia Subduction Zone is capable of producing a magnitude 9.0+ megathrust earthquake. Scientists say it’s overdue—by about 100 years. When it finally slips, the quake could last minutes, devastate infrastructure, and trigger a tsunami that ravages the Pacific Northwest coastline. Cities like Seattle and Portland, far less earthquake-prepared than their California counterparts, would be severely impacted.
What’s even more alarming is how quiet this fault has been—geologically speaking, that silence can signal tension building beneath the surface. FEMA has already run disaster simulations revealing thousands of potential deaths and billions in damages. Cascadia isn’t just a threat—it’s a ticking time bomb. And it’s one too few people are paying attention to.
2. The New Madrid Seismic Zone has a violent history of powerful inland quakes.
The New Madrid Seismic Zone, located in the central U.S. near Missouri, Arkansas, and Tennessee, is far from any coast—but it’s not free from seismic risk. In the winter of 1811–1812, a series of catastrophic quakes—estimated at magnitudes above 7.0—shook the region so violently that the Mississippi River briefly flowed backward. This area still experiences frequent tremors, and new research suggests that the fault system remains active.
Millions of people now live in its potential impact zone, yet building codes and preparedness lag far behind coastal states. A large quake here could cause major damage across eight states, disrupt the national power grid, and paralyze transportation routes. The Midwest may seem stable, but the New Madrid’s violent past says otherwise.
3. Alaska is the most seismically active state in the U.S.—and it’s only getting shakier.
Alaska doesn’t get the attention California does, but it’s actually the most earthquake-prone state in the country. In fact, three of the five largest quakes ever recorded in U.S. history occurred there. In July 2025, a 6.2-magnitude quake struck just days after another powerful temblor, raising fresh concerns about aftershock activity and infrastructure resilience. While Alaska’s remote terrain may limit fatalities, ports, pipelines, and military installations are vulnerable.
Experts believe the region’s high tectonic stress levels are part of a larger global trend of seismic acceleration. As warming permafrost destabilizes ground conditions, the risks may increase even more. Alaska’s seismic unrest could have major ripple effects—including disruptions to oil supply lines and shipping routes that serve the entire nation.
4. Scientists warn that the Pacific Northwest is dangerously underprepared.
Unlike California, where seismic retrofitting and strict building codes are well-established, cities like Seattle and Portland are lagging behind. Many public schools, hospitals, and older buildings in the Pacific Northwest were not designed with earthquakes in mind. If a Cascadia quake hits, officials warn that bridges could collapse, emergency services could fail, and many structures may not withstand even moderate shaking. Local governments are scrambling to catch up, but progress is slow.
Emergency response drills are infrequent, and communication systems may be overwhelmed in a real crisis. This combination of high seismic risk and low preparedness is a recipe for catastrophe. Waiting for the earth to move before making changes could cost thousands of lives and billions of dollars.
5. Major population centers sit atop unreinforced faults outside California.
You might not realize it, but places like St. Louis, Memphis, Salt Lake City, and even Charleston, South Carolina, sit near active or recently reawakened fault lines. These cities aren’t as earthquake-savvy as Los Angeles or San Francisco, and many buildings there haven’t been reinforced for seismic events. A powerful quake in one of these regions could destroy infrastructure, displace hundreds of thousands of residents, and cripple critical services.
FEMA and the USGS have warned that urban areas far from California are dangerously unprepared for seismic events. The focus on California has created blind spots across the nation—ones that could have devastating consequences if these other regions start shaking.
6. Water and power systems in inland states aren’t built to handle seismic shock.
Unlike California, which has invested billions in quake-proofing its utilities, many inland states haven’t made similar upgrades. A major quake in the Midwest or Pacific Northwest could rupture gas lines, destroy water mains, and knock out power stations, leaving millions without basic services. In cold-weather regions, losing heat or water for even a few days could turn deadly. Emergency response plans may also be limited, particularly in rural areas where resources are already stretched thin.
Infrastructure modernization has long been delayed due to cost or political gridlock—but the risks are growing. A single earthquake could cripple entire regions’ ability to provide clean water, power, and communication.
7. Most Americans outside California don’t have earthquake insurance—and they’ll pay the price.
Because many people outside the West Coast don’t think they live in earthquake zones, they skip the insurance—leaving them financially vulnerable. In Missouri, Arkansas, and Tennessee, for example, earthquake insurance rates are under 15%. Yet FEMA has warned that a major quake in the New Madrid region could cause over $100 billion in damage and affect more than 45 million people.
Homeowners who lose property may get little or no federal aid, and rebuilding could take years—if it happens at all. As awareness grows, some insurers are raising premiums or pulling out of high-risk zones altogether. When the shaking starts, uninsured Americans could face financial ruin.
8. The national response system isn’t designed for a non-California megaquake.
Most federal earthquake response planning has centered on California, where the risk is best known. But if the next big quake strikes the central U.S. or Pacific Northwest, agencies may struggle to respond effectively. Logistics, medical aid, and search-and-rescue teams may be slow to deploy in areas without robust infrastructure or experience handling major disasters. Supply chains could falter, and hospitals may lack surge capacity.
The federal government’s own simulations show gaps in communications, fuel availability, and coordination. In short, we’re not ready for a major quake in the “wrong” place—and that lack of preparation could make a bad disaster exponentially worse.