Central Virginia Seismic Zone Map

Map of the Central Virginia seismic zone and surrounding region, using polyconic projection with latitude and longitude lines added for orientation; dark rectangle is Pendleton and Ferncliff 7.5' quadrangles, and area of Figure 4. Shown are geographic and post-Paleozoic tectonic features of the Central Virginia seismic zone and surrounding area on 30 m DEM base, showing epicenters of historic and recent earthquakes and known sites of paleoliquefaction. White stars: epicenters of historic earthquakes from Tarr and Wheeler (2006). Filled white stars: instrumented locations with error bars of ~10 km radius, scaled to approximate magnitude with larger magnitudes shown; largest white star near center of map is epicenter of 2011 Mineral, Virginia, earthquake. Unfilled white stars: pre-instrument locations of earthquakes estimated at greater than M4 and possessing error bars in unknown excess of 10 km. Small gold circles: aftershocks from the 2011 M5.8 earthquake. Three blue hexagons: possible paleoliquefaction sites from Obermeier and McNulty (1998). Yellow lines: Jurassic diabase dikes. Solid white lines: known (solid) post-Triassic brittle faults. Dashed white lines: conspicuous linear scarps of unknown origin visible on 30 m DEM that have possible neotectonic origin. Stafford fault zone shown as black lines immediately east of the DEM base map (Figure from Burton et al, 2014 and modified from Mixon and Newell, 1977; Mixon et al., 2000; and Tarr and Wheeler, 2006).