Brookhaven, PA: what USGS's seismic model says

Under the seismic model IBC and ASCE 7 use for new construction, Brookhaven is Category B. Low seismic hazard. Code requires basic seismic detailing (bracing, connections) but no special structural system restrictions. That puts Brookhaven in the 56th percentile nationally for seismic hazard - higher than 56% of the 4,875 US cities USGS was checked against here.

Where Brookhaven sits in Pennsylvania

USGS's underlying values for Brookhaven: 0.1g peak ground acceleration, 0.181g at short period, 0.047g at 1 second. Within Pennsylvania alone, Brookhaven ranks 36 of 193 cities by seismic hazard - the 82th percentile in-state. Brookhaven has a population of about 8,407.

What a retrofit costs in Brookhaven

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 Pennsylvania 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 Pennsylvania.

What this means for insurance

A Brookhaven 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 Brookhaven's figures come from

Brookhaven'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 Brookhaven.