Myrtle Beach's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Myrtle Beach 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. Nationally, Myrtle Beach ranks above 75% of the 4,875 cities in this dataset for seismic hazard - the 75th percentile.

How Myrtle Beach compares

The raw figures: peak ground acceleration 0.16g, short-period spectral response 0.303g, 1-second spectral response 0.111g. Among 66 South Carolina cities in this dataset, Myrtle Beach ranks 47 for seismic hazard, the 29th percentile within the state. About 40,535 people live in Myrtle Beach, South Carolina.

Bracing and bolting: the actual cost

Outside California, no state-level retrofit grant equivalent to Brace + Bolt could be found for South Carolina. 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 Myrtle Beach address.

More on how this number was built

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