Does Hannibal, MO need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Hannibal in Seismic Design Category C: Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. That puts Hannibal in the 67th percentile nationally for seismic hazard - higher than 67% of the 4,875 US cities USGS was checked against here.

How Hannibal compares

The raw figures: peak ground acceleration 0.07g, short-period spectral response 0.148g, 1-second spectral response 0.088g. Among 135 Missouri cities in this dataset, Hannibal ranks 92 for seismic hazard, the 32th percentile within the state. About 16,809 people live in Hannibal, Missouri.

Retrofit economics for Hannibal

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Missouri. A typical retrofit still runs $5,000-$10,000 nationally, about $7,000 for a common single-family job.

What this means for insurance

Outside California, earthquake coverage is typically sold as an endorsement added to a standard homeowners policy, not a separate product - worth asking about directly when getting a home-insurance quote for a Hannibal address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Hannibal's numbers. The guide to what a Seismic Design Category actually means covers why a category is never a substitute for an engineer's assessment of one specific house.