Madison, AL: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Madison 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. Rank it against the rest of the country and Madison sits at the 73th percentile for seismic hazard among 4,875 US cities.

Where Madison sits in Alabama

USGS's underlying values for Madison: 0.133g peak ground acceleration, 0.261g at short period, 0.118g at 1 second. Within Alabama alone, Madison ranks 58 of 107 cities by seismic hazard - the 46th percentile in-state. Madison has a population of about 64,029.

Retrofit economics for Madison

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 Alabama 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 Alabama.

What this means for insurance

A Madison 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 Madison's figures come from

Madison'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 Madison.