USGS to map faults in Va.

LOUSIA, Va. (AP) - Scientists with the U.S. Geological Survey plan to map underground faults in Virginia that caused last year's earthquake.

The mapping will be done with a low-flying airplane carrying instruments that will measure gravitational and magnetic pull at different sites. The agency says it's the first time that airborne gravity will be used as a tool in the U.S. to map a seismic hazard.

The 5.8-magnitude earthquake on Aug. 23, 2011, was centered in Louisa County.

The flight surveys will be conducted in Louisa, Goochland and Fluvanna counties. Depending on weather, the flights could begin Tuesday and continue until July 20.

Data collected during the survey will allow the agency to refine its estimates of the region's seismic hazard.

WVIR-TV says the agency announced the survey Monday.