Clarksville's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Clarksville is 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 Clarksville in the 69th percentile nationally for seismic hazard - higher than 69% of the 4,875 US cities USGS was checked against here.

Clarksville by the numbers

The raw figures: peak ground acceleration 0.098g, short-period spectral response 0.199g, 1-second spectral response 0.099g. Among 126 Indiana cities in this dataset, Clarksville ranks 35 for seismic hazard, the 73th percentile within the state. About 22,041 people live in Clarksville, Indiana.

Retrofit economics for Clarksville

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

Earthquake insurance for a Clarksville home

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 Clarksville address.

More on how this number was built

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