Earthquakes risk in Illinois

Illinois and the New Madrid Seismic Zone

You're standing in the basement of a 1920s bungalow in Carbondale, and the inspector points to a hairline crack in the foundation. It's not from settling, he says — it's from the last time the ground moved. Illinois gets a 2 out of 5 on our statewide earthquake risk scale, which sounds low until you realize that the New Madrid Seismic Zone in neighboring Missouri and the Wabash Valley Seismic Zone along the Indiana line have produced some of the largest earthquakes in U.S. history. The risk is real, especially in the southern third of the state.

Counties like Alexander, Pulaski, Massac, Hardin, Pope, Johnson, Union, Jackson, Williamson, Saline, and Gallatin sit closest to the action. But even Chicago and Peoria feel occasional tremors. The U.S. Geological Survey (USGS) tracks this activity, and the Illinois Emergency Management Agency (IEMA) coordinates the state's response. If you're buying a house in Cairo, Metropolis, or Marion, you should know what your insurance does and doesn't cover.

What actually happens to a house

Most Illinois earthquakes are small — a rattle, a picture frame askew. But a magnitude 6 or 7 on the New Madrid fault could shake homes for hundreds of miles. In a typical wood-frame house, the weakest points are the foundation bolts, unreinforced chimneys, and water heaters. You might see cracks in drywall, a chimney separate from the wall, or a gas line rupture that leads to fire. Brick veneer can peel away. Older homes with cripple walls or unbraced foundations are more vulnerable.

The ground itself can also fail. In the Mississippi River floodplain, liquefaction is possible — soil behaves like a liquid, causing foundations to sink or tilt. That's a bigger problem in the bootheel region than in the Chicago suburbs. But the shaking doesn't stop at the state line.

If you only do three things

With limited time and money, here's what I'd do first:

1. Bolt your house to its foundation. A licensed contractor can install anchor bolts and plates for a few thousand dollars. If you're handy, you can do it yourself with a hammer drill and epoxy. This single step keeps your house from sliding off.
2. Strap your water heater. Two metal straps and a wrench cost about $30. A falling water heater can start a fire or flood your home. It's the cheapest earthquake upgrade you can make.
3. Buy earthquake insurance — or at least read your policy. Your standard homeowners policy excludes earth movement. You'll need a separate endorsement or policy. Deductibles are often 5–15% of your dwelling coverage, so a $300,000 home could mean a $15,000–$45,000 deductible. That's not for everyone, but in southern Illinois it's worth pricing out.

Questions we get

Does Illinois really have earthquakes?

Yes. The USGS records hundreds of small quakes in the region each year, most too weak to feel. The New Madrid Seismic Zone, centered near Sikeston, Missouri, produced a series of magnitude 7–8 earthquakes in 1811–1812 that rang church bells in Boston. The Wabash Valley Seismic Zone has also produced magnitude 5+ events. So while Illinois isn't California, it's not quiet either.

Is earthquake insurance worth it in Illinois?

It depends on where you live. If you're in Alexander, Pulaski, or Massac County, the risk is higher, and a policy might cost a few hundred dollars a year. In Chicago, the risk is lower, but a policy is still cheap. The catch is the deductible. Many Illinois insurers offer earthquake coverage with a 5% deductible. Run the numbers: if a quake would cost you $50,000 to repair, and your deductible is $15,000, you're covered for $35,000. That might be worth it. But if you have a newer home with a bolted foundation and a strapped water heater, you might self-insure.

What should I do during an earthquake in Illinois?

Drop, cover, and hold on. Get under a sturdy table or desk, protect your head and neck, and stay there until the shaking stops. If you're in bed, stay there and cover your head with a pillow. Don't run outside — most injuries happen when people try to move during the shaking. After it stops, check for gas leaks and damage. If you smell gas, leave immediately. Ready.gov has a full checklist.

Where to verify this

Don't take my word for it. Check the official sources:

• Illinois Emergency Management Agency (IEMA)
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety

One last thing: earthquake risk in Illinois is not a reason to panic. It's a reason to spend a weekend bolting your house and strapping your water heater. That's the practical move.