Virginia seismic zones

The Virginia seismic zones in the U.S. state of Virginia include the Giles County seismic zone and the Central Virginia seismic zone. Earthquakes in the state are irregular and rarely reach over 4.5 in magnitude.

1897 event

The May 31, 1897, event was the strongest in Virginia's history. With a maximum Mercalli intensity of VIII (Severe) this shock destroyed many chimneys and created ground effects over a large area. It had a magnitude of 5.6 Mfa (a seismic scale that is based on an isoseismal map or the event's felt area) and had severe effects in Narrows, where ground motion was observed and the flow of streams was disrupted.[1]

2003 earthquakes

On December 9, 2003, at 3:59 pm EST (20:59 UTC), a magnitude 4.5 event occurred near Farmville about 30 miles (48 km) west of Richmond, and was felt strongly across the state. Tremors were reported in North Carolina, Washington DC, and suburban Maryland, eastern West Virginia, southern Pennsylvania, and portions of the Delmarva Peninsula. This event was located at 37.728° N, 78.087° W, at a depth of less than 5 km (3.1 mi) and may have occurred due to rupture along the Lakeside fault.[2]

2011 earthquake

Main article: 2011 Virginia earthquake

The U.S. Geological Survey (USGS) reported that a magnitude 5.8 Mw earthquake hit Virginia on Tuesday, August 23, 2011, at 17:51:04 UTC (1:51 pm Eastern Daylight Time). The quake occurred at an approximate depth of 3.7 miles and was centered in Louisa County (location at 37.936°N, 77.933°W), 5 miles SSW of Mineral, Virginia and 37 miles NW of Richmond, Virginia's capital.[3] Shaking was felt from Atlanta, Georgia to Illinois to Detroit, Michigan to Barrie, Ontario to New Brunswick.[4][5] Many Washington, DC buildings saw precautionary evacuations.[6][7] The earthquake caused an estimated $70 million in damage in Louisa County and forced Louisa County High School and Thomas Jefferson Elementary School to close for the year as well as rendered about a dozen homes unlivable.[8][9] Other buildings were damaged as far away as Prince George's County, Maryland. Three decorative pinnacles at Washington National Cathedral fell.[10] The Washington Monument was closed due to cracks in the top section.[11][12]

See also

References

  1. ^ Stover, Carl W.; Coffman, Jerry L. (1993), Scott, Richard W. Jr. (ed.), Seismicity of the United States, 1568–1989 (Revised), U.S. Geological Survey professional paper, vol. 1527, United States Government Printing Office, pp. 376–378, OCLC 26363877
  2. ^ "Virginia earthquake not a fluke in the seismically active Southeast". ScienceBlog. December 2003. Retrieved February 21, 2011.
  3. ^ "Magnitude 5.8 – VIRGINIA". Earthquake Hazards Program. United States Geological Survey. March 20, 2012. Archived from the original on March 29, 2012. Retrieved April 6, 2012.
  4. ^ "USGS Community Internet Intensity Map: Virginia" (PDF). Earthquake Hazards Program. United States Geological Survey. Archived from the original (PDF) on December 27, 2011.
  5. ^ "M5.8 – Virginia". Earthquake Hazards Program. United States Geological Survey. November 30, 2011. Archived from the original on April 28, 2012. Retrieved April 6, 2012.
  6. ^ "Quake rocks Washington area, felt on East Coast". Associated Press (AP). August 23, 2011. Archived from the original on October 9, 2018. Retrieved August 23, 2011.
  7. ^ "Strong earthquake hits Canada, U.S. East Coast". Vancouver Sun. August 23, 2011.[dead link‍]
  8. ^ "Louisa damage estimate $70 million". Richmond Times Dispatch. August 30, 2011. Archived from the original on February 4, 2013.
  9. ^ Kreuz, Greta (August 30, 2011). "Earthquake damage to Louisa County schools close to $60M". ABC 7 News. Sinclair Broadcast Group.
  10. ^ "Earthquake at 6 Months". Washington National Cathedral. Archived from the original on April 1, 2012. Retrieved April 6, 2012.
  11. ^ Achenbach, Joel (August 23, 2011). "5.8 Virginia earthquake shakes East Coast, rattles residents". The Washington Post. p. 2. Retrieved January 10, 2012.
  12. ^ "Washington Monument Earthquake Update". National Park Service.

37°43′41″N 78°05′13″W / 37.728°N 78.087°W / 37.728; -78.087