2011 Virginia Earthquake
Tens of millions of people felt the M5.8 earthquake that occurred in Louisa County, VA on August 23, 2011. The earthquake occurred on a fault that had not previously been known, and no corresponding surface rupture was observed. To map the lateral extent of the fault and associated geologic structures, the USGS commissioned high-resolution airborne magnetic, gravity and radiometric (gamma-ray spectroscopy) as well as lidar surveys over the epicentral region.