Portsmouth, OH: what USGS's seismic model says

Portsmouth carries Seismic Design Category B under USGS's ASCE 7-16 model. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. Nationally, Portsmouth ranks above 49% of the 4,875 cities in this dataset for seismic hazard - the 49th percentile.

How Portsmouth compares

USGS's underlying values for Portsmouth: 0.077g peak ground acceleration, 0.15g at short period, 0.069g at 1 second. Within Ohio alone, Portsmouth ranks 58 of 254 cities by seismic hazard - the 77th percentile in-state. Portsmouth has a population of about 17,489.

Retrofit economics for Portsmouth

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 Ohio 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 Ohio.

Insuring against this, not just retrofitting

A Portsmouth 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 Portsmouth's figures come from

Portsmouth'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 Portsmouth.