Virginia Tech Seismological Observatory VTSO

Louisa County Aftershock: March 15, 2015

A small, shallow focus earthquake occurred on March 15, 2015 near the town of Mineral, Virginia, in Louisa County. The earthquake occurred in the aftershock zone of the magnitude Mw 5.7 August 23, 2011 Mineral earthquake. The U.S. Geological Survey reported a magnitude of 2.8. The duration magnitude determined by VTSO is 3.1 +/- 0.2, based on 7 stations, and the mbLg magnitude estimate is 3.2 +/- 0.2, based on 7 observations in the distance range from 36 to 233 km. The VTSO magnitude estimate is more consistent with the felt reports provided by the public, and the magnitudes of many similar shocks recorded in the Central Virginia Seismic Zone since 1978. The VTSO hypocenter location is:

Origin time: 2015/03/15, 07:02:35.8 UTC (March 25, 2015, 03:02:35.8 AM EDT).

Latitude: 37.9590 N
Longitude: 77.9502 W
Focal depth: 5.6 km

The horizontal location error estimate is 1.2 km (68% confidence interval).
The error estimate for the focal depth is 2.7 km (68% confidence interval).

The earthquake was reported felt in Louisa County. No damage was reported.


Seismograms From Nearby Stations

seismograms for Louisa County aftershock July 2014

USGS "Did You Feel It" Map

USGS DYFI map for this event.