Sitka's Seismic Design Category, explained

Sitka carries Seismic Design Category D under USGS's ASCE 7-16 model. 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. Rank it against the rest of the country and Sitka sits at the 85th percentile for seismic hazard among 4,875 US cities.

Where Sitka sits in Alaska

USGS's underlying values for Sitka: 0.298g peak ground acceleration, 0.875g at short period, 0.601g at 1 second. Within Alaska alone, Sitka ranks 8 of 11 cities by seismic hazard - the 30th percentile in-state. Sitka has a population of about 8,355.

Retrofit economics for Sitka

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 Alaska 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 Alaska.

Earthquake insurance for a Sitka home

A Sitka 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 Sitka's figures come from

Sitka'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 Sitka.