Greencastle, IN: what USGS's seismic model says
USGS's ASCE 7-16 seismic design model - the same standard building codes use - places Greencastle in Seismic Design Category C: Moderate seismic hazard. Code adds irregular-building restrictions and requires bracing of some nonstructural components (e.g. tall shelving, water heaters) in addition to structural detailing. That puts Greencastle in the 71th percentile nationally for seismic hazard - higher than 71% of the 4,875 US cities USGS was checked against here.
How Greencastle compares
USGS's underlying values for Greencastle: 0.112g peak ground acceleration, 0.223g at short period, 0.099g at 1 second. Within Indiana alone, Greencastle ranks 18 of 126 cities by seismic hazard - the 86th percentile in-state. Greencastle has a population of about 9,907.
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 Indiana 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 Indiana.
Earthquake insurance for a Greencastle home
A Greencastle 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 Greencastle's figures come from
Greencastle's Category C 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 C does and doesn't tell you about Greencastle.