Virginia Seismic Zone

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The Virginia Seismic Zone is located in the US State of Virginia. Earthquakes in Virginia are irregular and rarely above 4.5 on the Richter magnitude scale.

[edit] List of Earthquakes

• 1774-02-21. Near Petersburg, Prince George County. A sharp earthquake that was felt over much of Virginia displaced houses "considerably off their foundations" at Blandford and Petersburg. Although the shock was severe at Richmond and terrified residents about 80 km north of Richmond at Fredericksburg, it caused no damage at those towns. Several "smart shocks" were reported in parts of Virginia from Feb. 20th to the 22nd. The main tremor rang bells at Salem (now Winston-Salem), North Carolina. Magnitude 4.5
• 1833-08-27. Central Virginia. A rather strong shock agitated walls of buildings at Lynchburg (west of Richmond, in southern Amherst County) and rattled windows violently. Fences along the road were shaken near the Louisa County Courthouse, northwest of Richmond. It was described as "severe" at Charlottesville, about 85 km northeast of Lynchburg. Two miners were killed in a panic caused by the tremor at a mine near Richmond. Ref. 179 suggests a MM intensity VI at the epicenter, although no damage was documented. Also felt in the District of Columbia, Maryland, and North Carolina. Magnitude 4.5
• 1852-04-29. Near Wytheville, Wythe County. A severe earthquake that was observed over a large area threw down a chimney near Wytheville, in southwest Virginia, and shook down tops of chimneys at Buckingham Courthouse, about 55 km south of Charlottesville. Houses were shaken violently at Staunton, about 65 km west of Charlottesville. A brick was shaken from a chimney as far south as Davie County, North Carolina. Also felt in the District of Columbia, Maryland, New York, Ohio, and Pennsylvania. Magnitude 4.9
• 1852-04-02. Central Virginia. Chimney damage occurred at Buckingham, about 55 km south of Charlottesville. This earthquake was reported to be "quite strong" at Fredericksburg, Richmond, and Scottsville. At Scottsville, where every house in the village was shaken, water in the canal was "troubled," and boats were tossed to and fro. Magnitude 4.3
• 1875-12-23 (Dec. 22). Central Virginia. The highest intensities from this earthquake occurred mainly at towns near the James River waterfront in Goochland and Powhatan Counties, and in Louisa County. In Richmond (Henrico County), the most severe damage was sustained in the downtown business and residential areas adjacent to the James River or on islands in the river. Damage included bricks knocked from chimneys, fallen plaster, an overturned stove, and several broken windows. Waves "suddenly rose several feet" at the James River dock at Richmond, causing boats to "part their cables" and drift below the wharf. At Manakin, about 20 km west of Richmond, shingles were shaken from a roof and many lamps and chimneys were broken. Several small aftershocks were reported through 1876-01-02. Felt from Baltimore, Maryland, to Greensboro, North Carolina, and from the Atlantic Coast westward to Greenbrier County and White Sulphur Springs, West Virginia. Magnitude 4.5
• 1897-05-03. Southwest Virginia. This earthquake was most severe at Radford (about 65 km west of Roanoke), where a few chimneys were wrecked and plaster fell from walls. Chimneys were damaged at nearby Pulaski and at Roanoke. Felt in most of southwest Virginia and as far south as Winston-Salem, North Carolina. Magnitude 4.3.)
• 1897-05-31. Giles County. This earthquake was the largest in intensity and areal extent in Virginia in historical times. The earthquake had a maximum Modified Mercalli Intensity of VIII, and the area of maximum ground motion extended over an elliptical area-from near Lynchburg, Virginia, west to Bluefield, West Virginia, and from Giles County south to Bristol, Tennessee. The MM intensity VIII assigned to this earthquake is based on "many downed chimneys" and "changes in the flow of springs." The shock was felt severely at Narrows, about 3 km west of Pearisburg. Here, the surface rolled in an undulating motion, water in springs became muddy, and water in some springs ceased to flow. The flow of water in springs also was disturbed in the area of Pearisburg, about 70 km west of Roanoke, and Sugar Run. The shock was strong at Pearisburg, where walls of old brick houses were cracked and many chimneys were thrown down or badly damaged. Many chimneys also were shaken down at Bedford, Pulaski, Radford, and Roanoke, Va., and Bristol, Tenn.; many chimneys were damaged at Christiansburg, Dublin, Floyd, Houston, Lexington, Lynchburg, Rocky Mount, Salem, Tazewell, and Wytheville, Va.; Charlotte, Oxford, Raleigh, and Winston, N.C.; Knoxville, Tenn.; and Bluefield, W.Va. Felt from Georgia to Pennsylvania and from the Atlantic Coast westward to Indiana and Kentucky. Aftershocks continued through June 6, 1897. Magnitude 5.8 Mfa NUT.
• 1898-02-05. Pulaski, Virginia. Bricks were thrown from chimneys, furniture was shifted in a few houses, and residents rushed into the streets at Pulaski, about 70 km southwest of Roanoke. Felt throughout southwest Virginia and south to Raleigh, N.C.
• 1907-02-11. Near Arvonia, Buckingham County. Chimneys were cracked at Ashby, about 20 km southeast of Arvonia, and a window was broken at a store at Buckingham, 25 km southwest of Arvonia. A "terrific" shock sent people rushing outdoors at Arvonia and displaced furniture. Felt strongly from Powhatan to Albemarle County.
• 1918-04-10 (Apr. 9). Luray, Page County. In the Shenandoah Valley, at Luray, windows were broken and plaster was cracked severely. Ceilings of houses were cracked badly a few kilometers north of Luray, at Edinburg; windows were broken at Harrisonburg and Staunton, Va., and Washington, D.C. (at Georgetown University). In addition, a new spring formed in Page County, near Hamburg, almost in the middle of a road. A minor aftershock was reported in the area about 5 hours later. Also felt in Maryland, Pennsylvania, and West Virginia.
• 1919-09-06 (Sept. 5). Near Front Royal, Warren County. This earthquake affected towns mainly in Warren and Rappahannock Counties. At Arco, in the Blue Ridge Mountains south of Front Royal, chimneys were damaged, plaster fell from walls, and springs and streams were muddied. Reports from the adjacent northern part of Rappahannock County state that similar shocks were felt and that streams were "rendered turbid." Also felt in parts of Maryland and West Virginia. Several aftershocks occurred.
• 1929-12-26 (Dec. 25). Charlottesville, Albemarle County. A moderate tremor at Charlottesville shook bricks from chimneys in some places. Also felt in other parts of Albemarle County.
• 1959-04-23. Giles County. The earthquake was strongest in Giles County, at Eggleston and Pembroke. Residents there reported several damaged chimneys and articles shaken from shelves and walls. One chimney toppled at the Norfolk and Western Railway station in Eggleston. Also felt in West Virginia. Magnitude 3.8
• 1975-04-11. Southwest Virginia. Windows were broken in the Blacksburg area of Montgomery County, and plaster was cracked at Poplar Hill (south of Pearisburg, in Giles County). Also felt in Pulaski County.
• 1976-09-13. Southwest Virginia. Bricks fell from chimneys and pictures fell from walls in Surry County at Mount Airy, North Carolina. At the nearby town of Toast, North Carolina, cracks formed in masonry and plaster. The earthquake was observed in many towns in North Carolina and Virginia and in a few towns in South Carolina and West Virginia.
• 2003-12-09, The 2003 Virginia Earthquake was a magnitude 4.5 earthquake. It occurred on December 9 at 3:59 p.m. EST (20:59 UTC) in the foothills about 30 miles (48 kilometers) west of Richmond.

[edit] 2003 earthquake

a magnitude 4.5 earthquake. It occurred on December 9, 2003 at 3:59 p.m. EST (20:59 UTC) in the foothills about 30 miles (48 kilometers) west of Richmond, Virginia.

The earthquake felt strongly over almost all of Virginia, from the Shenandoah Valley to Hampton Roads. There was shaking reported in much of North Carolina, the District of Columbia, and suburban Maryland. Shaking was also reported in 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 miles) and may have occurred due to rupture along the Lakeside fault. It was preceded by a magnitude 3.8 event on May 5th, 2003 whose epicenter was located only a few kilometers away. this was a significant earthquake, the largest recorded in Virginia since the widespread use of modern seismic monitoring equipment in the early 1970's. The largest Virginia earthquake in recorded history occurred on May 31st, 1897 in Giles County and is estimated to have had a magnitude of 5.8.The earthquake caused little to no structural damage, but as a precaution, government buildings in Richmond were evacuated and inspected for damage.

The central Virginia Seismic Zone is a region of persistent seismic activity in the Piedmont province covering approximately 8,000 km² (~3,000 mi²). Earthquakes in the central Virginia Seismic Zone are relatively frequent, but generally of small size.

[edit] References