Earthquakes risk in Missouri

Earthquake Risk in Missouri: Geography and Exposure

Missouri has a genuine and serious earthquake risk, largely due to the New Madrid Seismic Zone (NMSZ) in the southeastern part of the state. This zone is the most active seismic area east of the Rocky Mountains and was responsible for some of the largest earthquakes in U.S. history in 1811–1812. The USGS Earthquake Hazards Program continuously monitors this and other faults. The NMSZ is centered near New Madrid, Missouri, and extends into Arkansas, Tennessee, Kentucky, and Illinois. The Bootheel region and the St. Louis metropolitan area are particularly exposed, but shaking from a major earthquake could be felt across a much wider area, including much of the Midwest. Missouri also has other seismic zones, such as the Wabash Valley Seismic Zone along the Illinois-Indiana border, which can affect eastern Missouri.

Earthquakes in this region can occur at any time of year; they are not seasonal. The deep sedimentary soils of the Mississippi Embayment can amplify shaking and cause damage far from the epicenter. According to the Missouri State Emergency Management Agency (SEMA), all Missourians should be aware of earthquake risk and know how to prepare. HomeRiskMap rates Missouri at a level 3 out of 5 for earthquake risk, indicating a moderate-to-high hazard that warrants attention from homeowners.

How It Affects Homes

Earthquakes can cause a wide range of damage to homes. Typical impacts include cracked foundations and walls, broken windows, toppled chimneys, and roof damage. Unsecured water heaters, appliances, and furniture can shift or fall, causing injuries and gas leaks that may lead to fires. Older homes, especially those with unreinforced masonry or brick veneer, are more vulnerable. Homes built on soft, saturated soils—common in the Mississippi River valley—may experience stronger shaking and greater damage. Even moderate earthquakes can cause structural cracks and costly repairs.

From an insurance perspective, standard homeowners policies do not cover earthquake damage. Homeowners in Missouri typically need to purchase a separate earthquake policy or add an endorsement to their existing policy. Deductibles for earthquake coverage are often a percentage of the home's dwelling coverage (for example, 5–10%), so it's important to understand your financial exposure. The FEMA Earthquake Safety page offers guidance on assessing risk and mitigating damage. SEMA recommends contacting your insurance agent to discuss available options and to document your belongings with photos or a video.

How to Prepare Your Home

You can take concrete steps to reduce damage and protect your family. Consider the following mitigation measures, recommended by Ready.gov and FEMA:

1. Bolt and brace your home: Ensure your house is bolted to its foundation and that cripple walls are braced. This is especially important for older homes. Consult a licensed contractor or structural engineer.
2. Secure your water heater: Strap the water heater to wall studs and use flexible connections for gas and water lines.
3. Anchor large appliances and furniture: Secure refrigerators, bookcases, televisions, and other heavy items to walls with brackets, straps, or anchors.
4. Reinforce chimneys: Have a professional evaluate and reinforce your chimney, or consider removing it if it is unreinforced.
5. Install flexible gas connectors and automatic gas shut-off valves: These can prevent fires after an earthquake.
6. Secure cabinets: Use childproof latches or other secure latches to keep cabinet doors closed.
7. Create an emergency kit: Include water, non-perishable food, medications, flashlight, battery-powered radio, and first-aid supplies. Store it in an accessible location.
8. Practice Drop, Cover, and Hold On: Make sure everyone in your household knows what to do during an earthquake. Participate in the Great ShakeOut drill.
9. Consider a professional inspection: A structural engineer can identify weaknesses and suggest retrofits specific to your home.
10. Review insurance coverage: Talk to your agent about earthquake insurance and understand deductibles and exclusions.

Frequently Asked Questions

Is Missouri really at risk for earthquakes?

Yes. The New Madrid Seismic Zone is active and capable of producing large earthquakes. The USGS and SEMA both recognize significant risk. Even if you don't live in the Bootheel, shaking from a major event could affect your home. Missouri is rated level 3 out of 5 for earthquake risk by HomeRiskMap, meaning the hazard is moderate-to-high.

Does homeowners insurance cover earthquake damage in Missouri?

No, standard homeowners insurance policies typically exclude earthquake damage. You will need a separate earthquake policy or an endorsement. Coverage and deductibles vary, so shop around and ask your agent specifically about earthquake coverage. SEMA and FEMA recommend documenting your belongings in advance.

What should I do during an earthquake to stay safe?

Drop, Cover, and Hold On. Get under a sturdy table or desk, protect your head and neck, and hold on until shaking stops. If indoors, stay away from windows and heavy objects. If outdoors, move away from buildings, power lines, and trees. Ready.gov – Earthquakes provides detailed guidance for before, during, and after an earthquake.

Official Resources

• Missouri State Emergency Management Agency (SEMA)
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety