A geologic hazard or "geohazard" is a geologic condition, either manmade or natural, that poses a potential danger to life and property. Ohio is home to a number of potential geohazards, including karst (caves and sinkholes), mine subsidence, earthquakes, landslides, and shore erosion. To avoid or mitigate geologic hazards, a fundamental understanding of the geology of the affected area is required. Geohazards are investigated by the ODNR Division of Geological Survey.
Geologic maps produced by the Division, which depict glacial or bedrock deposits, can provide contextual information that can be transferred into useful geohazards mapping. For example, maps that show the Columbus Limestone exposed at the surface also depict areas subject to karst development, and maps that show shale-rich Ordovician bedrock present on steep slopes in southwest Ohio also indicate landslide-prone areas.