Earthquakes risk in Iowa

Earthquake Risk in Iowa: Low but Not Zero

Iowa sits in the midcontinent of the United States, far from major tectonic plate boundaries. As a result, the region experiences very few earthquakes and most are too small to be felt. The U.S. Geological Survey (USGS) maps earthquake hazard levels across the country, and Iowa ranks at the lowest level (1 out of 5) for shaking potential. This means that the chance of a damaging earthquake is extremely low compared to states like California or Alaska.

However, Iowans should not ignore the subject entirely. The state is near several ancient fault systems, such as the Nemaha Ridge and the Midcontinent Rift, which are still capable of generating small tremors. Historically, Iowa has experienced occasional minor earthquakes, usually with a magnitude below 3.5, which cause little or no damage. In rare cases, a slightly stronger earthquake (magnitude 4 to 5) could occur, and that might be felt across a wide area. Even though the risk is low, the USGS encourages all residents to know the basics of earthquake safety.

No specific season or geographic area in Iowa has a higher earthquake risk; earthquakes in the central U.S. can happen at any time of year, and shaking intensity is generally uniform across the state. The most exposed areas are those with older buildings that were not designed with seismic loads in mind, but the overall low hazard means that most modern homes are structurally safe.

How It Affects Homes

For most Iowa homeowners, an earthquake will never cause property damage. But because earthquakes are unpredictable, it is useful to understand what could happen if a moderate tremor struck a neighborhood. The typical effects on homes in a low-hazard zone include:

• Minor cracking: Drywall, plaster, and masonry foundations may develop small cracks.
• Shifting of items: Bookshelves, appliances, and heavy furniture could tip over or slide.
• Chimney damage: Unreinforced masonry chimneys are vulnerable to even moderate shaking.
• Gas leaks: A strong tremor could rupture natural gas lines, posing a fire hazard.
• Foundation settlement: In older homes with pier-and-beam or masonry foundations, shaking might cause minor movement.

Insurance considerations are important too. Standard homeowners insurance policies in Iowa generally do not cover earthquake damage. To be protected, homeowners would need to purchase a separate earthquake endorsement or policy. Given the low risk, this is often not a priority for Iowans, but it may be worth considering if you own an older home or have a high-value property. FEMA notes that in low-hazard areas, earthquake insurance is typically inexpensive, though deductibles can be high.

Even if damage is unlikely, taking a few simple steps can greatly reduce the risk of injury or loss during an earthquake. The cost of mitigation is low, and the peace of mind is valuable.

How to Prepare Your Home

Preparing for an earthquake in Iowa does not require major renovation. Instead, focus on securing your home and learning the correct response. Ready.gov and FEMA offer several practical recommendations that work well in any state, including Iowa.

• Secure heavy furniture: Use brackets or straps to attach bookshelves, cabinets, and televisions to wall studs.
• Anchor appliances: Strap water heaters, refrigerators, and stoves so they do not move during shaking.
• Install latches on cabinets: This keeps dishes and breakables from tumbling out.
• Check your foundation: If you have an older home with a masonry foundation, consult a professional about retrofitting it.
• Replace damaged wiring: Faulty wiring can spark fires if a quake shakes your home.
• Flexible gas connection: Install a flexible hose at your gas meter to reduce the chance of a leak.
• Create an emergency plan: Know where to take cover, and practice “Drop, Cover, and Hold On” with your family.
• Put together a kit: Keep water, food, a flashlight, and a first-aid kit in an accessible spot.

Remember that during an earthquake, your instinct may be to run outside, but it is safer to stay put. Get under a sturdy table and hold on until the shaking stops. In a low-rise home, that is the most effective way to avoid injuries from falling objects.

Frequently Asked Questions

Can a major earthquake happen in Iowa?

The short answer is very unlikely. The USGS shows that Iowa has a less than 1% chance of experiencing strong shaking from an earthquake in any given year. The state has no known active fault lines that have produced large earthquakes in recent geological history. While a moderate (magnitude 5) earthquake is possible, the probability is extremely low.

Should I buy earthquake insurance in Iowa?

Because the risk is so low, most Iowa homeowners do not purchase earthquake insurance. However, if your home is old, has a masonry foundation, or you cannot afford to repair even minor structural damage out of pocket, you may want to get a quote. An earthquake endorsement typically costs a few hundred dollars per year in low-risk states.

What is the best thing to do during an earthquake?

Always follow the “Drop, Cover, and Hold On” method taught by emergency management agencies. Drop to your hands and knees, take cover under a sturdy table or desk, and hold on to it until the shaking stops. Do not run outside, as you may be hit by falling debris.

Official Resources

• Iowa Homeland Security and Emergency Management
• USGS Earthquake Hazards Program
• Ready.gov – Earthquakes
• FEMA Earthquake Safety