EARTHQUAKE HAZARD CLASS MAPPING BY PARCEL IN UNINCORPORATED URBAN CLARK COUNTY

The Clark County Building Department has been recognized as one of the Nation's leading building-code enforcement agencies. Clark County is embarking on the Nation's very first effort to map earthquake hazard class systematically through an entire urban area. The resulting geotechnical shear-velocity map will become a layer added to the County's existing soil-hazards map. The map already includes layers such as fault proximity, ground subsidence, and potential for swelling clay soils. The new earthquake-hazard map layer will be available on the County's web GIS interface to all residents, and also to academics for hazard research. Geotechnical shear velocity is a basic building block in foundation design, and in predictions of potential for ground liquefaction, landslides, and seismic shaking, as a few examples. The map will be used in development and disaster response planning, in addition to its direct use for building code implementation and enforcement. Clark County is contracting with the University of Nevada to apply the refraction microtremor geophysical surveying technique, a State of Nevada-owned technology, to the hazard classification of about 500 square miles of its unincorporated urban area.