Marion's Seismic Design Category, explained

Marion carries Seismic Design Category C under USGS's ASCE 7-16 model. 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 75th percentile nationally for seismic hazard - higher than 75% of the 4,875 US cities USGS was checked against here.

How Marion compares

USGS's underlying values for Marion: 0.158g peak ground acceleration, 0.297g at short period, 0.11g at 1 second. Within South Carolina alone, Marion ranks 50 of 66 cities by seismic hazard - the 25th percentile in-state. Marion has a population of about 6,068.

Bracing and bolting: the actual cost

A full earthquake retrofit typically runs $5,000-$10,000 nationally (around $7,000 typical), driven mainly by house size and foundation type, not by South Carolina specifically. California's Earthquake Brace + Bolt grant, which covers a large share of this cost, is a California-only program and does not apply in South Carolina.

Earthquake insurance for a Marion home

A Marion homeowner cannot buy a standalone earthquake policy in most cases - it is added to an existing homeowners policy as an endorsement, so the place to start is a regular home-insurance quote.

Where Marion's figures come from

Marion's Category C and every number above trace to USGS's own ASCE 7-16 Design Maps service - see the methodology guide. See the category explainer for what Category C does and doesn't tell you about Marion.