Horn Lake's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Horn Lake in Seismic Design Category D: High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. That puts Horn Lake in the 89th percentile nationally for seismic hazard - higher than 89% of the 4,875 US cities USGS was checked against here.

Horn Lake by the numbers

The raw figures: peak ground acceleration 0.472g, short-period spectral response 0.805g, 1-second spectral response 0.278g. Among 61 Mississippi cities in this dataset, Horn Lake ranks 1 for seismic hazard, the 100th percentile within the state. About 26,574 people live in Horn Lake, Mississippi.

Retrofit economics for Horn Lake

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for Mississippi. 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 Horn Lake address.

More on how this number was built

The methodology guide covers exactly how USGS's public design-maps API produced Horn Lake'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.