Does Marion, NC need an earthquake retrofit?

USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Marion 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 Marion in the 74th percentile nationally for seismic hazard - higher than 74% of the 4,875 US cities USGS was checked against here.

How Marion compares

The raw figures: peak ground acceleration 0.142g, short-period spectral response 0.255g, 1-second spectral response 0.087g. Among 147 North Carolina cities in this dataset, Marion ranks 9 for seismic hazard, the 95th percentile within the state. About 7,534 people live in Marion, North Carolina.

Retrofit economics for Marion

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

Earthquake insurance for a Marion 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 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.