Does Blackwell, OK need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Blackwell in Seismic Design Category B: Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Rank it against the rest of the country and Blackwell sits at the 45th percentile for seismic hazard among 4,875 US cities.

How Blackwell compares

The raw figures: peak ground acceleration 0.071g, short-period spectral response 0.14g, 1-second spectral response 0.062g. Among 75 Oklahoma cities in this dataset, Blackwell ranks 49 for seismic hazard, the 35th percentile within the state. About 6,016 people live in Blackwell, Oklahoma.

Retrofit economics for Blackwell

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

Earthquake insurance for a Blackwell 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 Blackwell address.

More on how this number was built

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