Astoria's Seismic Design Category, explained

Under the seismic model IBC and ASCE 7 use for new construction, Astoria is Category D. High seismic hazard - this is the category most of coastal California, the Pacific Northwest, and other active fault regions fall into. Code mandates significant seismic detailing and restricts irregular structural configurations. This is the category the Brace + Bolt scope (cripple-wall bracing, foundation bolting) is built for. That puts Astoria in the 94th percentile nationally for seismic hazard - higher than 94% of the 4,875 US cities USGS was checked against here.

Where Astoria sits in Oregon

USGS's underlying values for Astoria: 0.624g peak ground acceleration, 1.254g at short period, 0.656g at 1 second. Within Oregon alone, Astoria ranks 9 of 80 cities by seismic hazard - the 90th percentile in-state. Astoria has a population of about 9,906.

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 Oregon 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 Oregon.

Insuring against this, not just retrofitting

A Astoria 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 Astoria's figures come from

Astoria's Category D 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 D does and doesn't tell you about Astoria.