Port Arthur's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Port Arthur is 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 Port Arthur sits at the 19th percentile for seismic hazard among 4,875 US cities.

How Port Arthur compares

USGS's underlying values for Port Arthur: 0.037g peak ground acceleration, 0.077g at short period, 0.045g at 1 second. Within Texas alone, Port Arthur ranks 182 of 384 cities by seismic hazard - the 53th percentile in-state. Port Arthur has a population of about 55,799.

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 Texas 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 Texas.

What this means for insurance

A Port Arthur 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 Port Arthur's figures come from

Port Arthur's Category B 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 B does and doesn't tell you about Port Arthur.