Marion's Seismic Design Category, explained

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Marion in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Marion in the 41th percentile nationally for seismic hazard - higher than 41% of the 4,875 US cities USGS was checked against here.

How Marion compares

The raw figures: peak ground acceleration 0.064g, short-period spectral response 0.13g, 1-second spectral response 0.071g. Among 126 Indiana cities in this dataset, Marion ranks 86 for seismic hazard, the 32th percentile within the state. About 28,216 people live in Marion, Indiana.

Bracing and bolting: the actual cost

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.

Insuring against this, not just retrofitting

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 Marion address.

More on how this number was built

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