General Situation

At 1:51 p.m. EDT on August 23, 2011, a 5.8 Magnitude earthquake at a depth of approximately 6 kilometers occurred 34 miles southwest of Fredericksburg, Virginia. The earthquake occurred as reverse faulting on a north or northeast-striking plane within a previously recognized seismic zone, the Central Virginia Seismic Zone. The tremor was felt as far away as New York City, Detroit, Michigan and Atlanta, Georgia. Aftershocks ranging to magnitude 4.5 have been recorded.

The earthquake shook the entire Washington, DC area, causing several roof collapses, dislodged masonry and transportation issues; there were only minor reported injuries and no deaths reported. The earthquake caused significant concern about the status of infrastructure elements, especially within major metropolitan areas. Within Washington, DC, the Metrorail system, MARC, VRE and AMTRAK all reduced the speed of trains while track conditions were assessed, all Interstates and major roadways, tunnels and bridges underwent inspections to ensure structural integrity prior to resuming normal operations.

Structural damage assessments were also conducted throughout the city on buildings, including at least nine government building that remained closed the day following the earthquake. Some damage was reported at the Washington National Cathedral, Reagan National Airport, the Pentagon, and Howard University.

Department of the Interior Headquarters – Stuart Udall Building and the South Interior Building.

The Department of the Interior's Stuart Udall (Main Interior) Building and the South Interior Building were evacuated to permit the building engineers to assess damage from the earthquake. Structural engineers from the National Park Service and the General Service Administration spent the day following the earthquake performing a detailed inspection of both buildings. While some cosmetic damage was observed, the inspectors found no structural damage that would indicate a hazardous condition for employees in either building, and normal business operations resumed two days after the earthquake.

U.S. Geological Survey (USGS):

The USGS has continuously tracked all seismic activity related to the earthquake and tracked the progress and amplitude of the aftershocks. The USGS held calls to coordinate post-earthquake investigations by the four National Earthquake Hazards Reduction Program agencies and their government and academic partners, and continues to research the faults and aftershocks.  USGS scientists also provided media interviews as well as participating in White House coordination meetings.No damage to USGS facilities or personnel injuries were reported and USGS leadership coordinated an assessment of the structural integrity of the USGS Headquarters in Reston, VA prior to resumption of normal operations.

The Patuxent National Wildlife Refuge suffered minor damages, but no other significant damage was reported, and no injuries or deaths were reported on FWS lands. FWS completed a post-earthquake assessments to determine effects of the earthquake on FWS-owned dams throughout the region. There was no need to implement an Emergency Action Plan and normal business operations resumed shortly.

 National Park Service:

Several facilities within the National Capital Region and the greater area affected by the earthquake sustained damage and required various degrees of inspection and rehabilitation prior to opening to the public. The most notable and severe damage occurred at that Washington Monument, which remains closed indefinitely due to cracks found in the stones at the top of the monument. The investigation included helicopter surveys immediately following the earthquake, and a more intense survey completed when structural engineers rappelled off the top of the monument to document the cracks and structural flaws throughout the monument's height. Work continues to plan the restoration of the monument. 

Updated as of  February 6, 2012