Virginia seismic zones

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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.

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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

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

Related Research Articles

The Modified Mercalli intensity scale measures the effects of an earthquake at a given location. This is in contrast with the seismic magnitude usually reported for an earthquake.

<span class="mw-page-title-main">Louisa County, Virginia</span> County in Virginia, United States

Louisa County is a county located in the Commonwealth of Virginia. As of the 2020 census, the population was 37,596. The county seat is Louisa.

<span class="mw-page-title-main">Intraplate earthquake</span> Earthquake that occurs within the interior of a tectonic plate

An intraplate earthquake occurs in the interior of a tectonic plate, in contrast to an interplate earthquake on the boundary of a tectonic plate. They are relatively rare compared to the more familiar interplate earthquakes. Buildings far from plate boundaries are rarely protected with seismic retrofitting, so large intraplate earthquakes can inflict heavy damage. Examples of damaging intraplate earthquakes are the devastating 2001 Gujarat earthquake, the 2011 Christchurch earthquake, the 2012 Indian Ocean earthquakes, the 2017 Puebla earthquake, the 1811–1812 New Madrid earthquakes, and the 1886 Charleston earthquake. An earthquake that occurs within a subducting plate is known as an intraslab earthquake.

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<span class="mw-page-title-main">New Madrid seismic zone</span> Major seismic zone in the southern and midwestern United States

The New Madrid seismic zone (NMSZ), sometimes called the New Madrid fault line, is a major seismic zone and a prolific source of intraplate earthquakes in the Southern and Midwestern United States, stretching to the southwest from New Madrid, Missouri.

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<span class="mw-page-title-main">2003 Alabama earthquake</span> Earthquake near Fort Payne, Alabama in 2003

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<span class="mw-page-title-main">Wabash Valley seismic zone</span> Tectonic region in the Midwestern United States

The Wabash Valley seismic zone is a tectonic region located in the Midwestern United States, centered on the valley of the lower Wabash River, along the state line between southeastern Illinois and southwestern Indiana.

The geology of Alabama is marked by abundant geologic resources and a variety of geologic structures from folded mountains in the north to sandy beaches along the Gulf of Mexico coast. Alabama spans three continental geologic provinces as defined by the United States Geological Survey, the Atlantic Plain, Appalachian Highlands, and Interior Plains. The Geological Survey of Alabama breaks these provinces down into more specific physiographic provinces.

The Eastern Tennessee seismic zone (ETSZ), also known as the East Tennessee seismic zone and the Southern Appalachian seismic zone, is a geographic band stretching from northeastern Alabama to southwestern Virginia that is subject to frequent small earthquakes. The ETSZ is one of the most active earthquake zones in the eastern United States.

<span class="mw-page-title-main">Western Quebec seismic zone</span>

The Western Quebec Seismic Zone is a seismically active area in the Ottawa Valley in Eastern Ontario and Western Quebec. The zone stretches from Montreal to Témiscaming and from Cornwall up along the Laurentian Mountains.

<span class="mw-page-title-main">1916 Irondale earthquake</span> Earthquake in Alabama on October 18, 1916

The 1916 Irondale earthquake struck in the north-central region of the U.S. state of Alabama on October 18. The strongest earthquake in state history, it registered an estimated Richter scale magnitude of 5.1 and resulted in minor damage. Damage was limited to Shelby and Jefferson counties and reached its maximum severity near the epicenter in the city of Irondale, including cracked windows, fallen chimneys, and dried-up wells. While there were no fatalities, the earthquake spawned widespread panic, prompting alarmed workers to evacuate tall buildings.

<span class="mw-page-title-main">2011 Virginia earthquake</span> Earthquake in Virginia, U.S.

On August 23, 2011, a magnitude 5.8 earthquake hit the Piedmont region of the U.S. state of Virginia at 1:51:04 p.m. EDT. The epicenter, in Louisa County, was 38 mi (61 km) northwest of Richmond and 5 mi (8 km) south-southwest of the town of Mineral. It was an intraplate earthquake with a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale. Several aftershocks, ranging up to 4.5 Mw in magnitude, occurred after the main tremor.

<span class="mw-page-title-main">2011 Oklahoma earthquake</span> 2011 earthquake near Prague, Oklahoma

The 2011 Oklahoma earthquake was a 5.7 magnitude intraplate earthquake which occurred near Prague, Oklahoma on November 5 at 10:53 p.m. CDT in the U.S. state of Oklahoma. The epicenter of the earthquake was in the vicinity of several active wastewater injection wells. According to the United States Geological Survey (USGS), it was the most powerful earthquake ever recorded in Oklahoma until the 2016 Oklahoma earthquake. The previous record was a 5.5 magnitude earthquake that struck near the town of El Reno in 1952. The quake's epicenter was approximately 44 miles (71 km) east-northeast of Oklahoma City, near the town of Sparks and was felt in the neighboring states of Texas, Arkansas, Kansas and Missouri and even as far away as Tennessee and Wisconsin. The quake followed several minor quakes earlier in the day, including a 4.7 magnitude foreshock. The quake had a maximum perceived intensity of VIII (Severe) on the Mercalli intensity scale in the area closest to the epicenter. Numerous aftershocks were detected after the main quake, with a few registering at 4.0 magnitude.

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The 1934 Hansel Valley earthquake occurred on March 12 at approximately 8:05 a.m. MST with a moment magnitude of 6.6 and a maximum Mercalli intensity of VIII (Severe). The shock originated in the Hansel Valley at the north end of the Great Salt Lake in Utah in the United States. Damage was mostly confined to vulnerable buildings, and two people died. The dip-slip (normal) fault that generated the shock ruptured the surface of the ground and other geologic features were documented. A large aftershock occurred three hours after the initial event and may have caused additional damage.

The 2020 Central Idaho earthquake occurred in the western United States on March 31, 2020, at 5:52 PM MDT, near Ruffneck Peak in the Sawtooth Mountains of central Idaho, 72 miles (116 km) northeast of Boise and 19 miles (31 km) northwest of Stanley. It had a magnitude of 6.5 and was felt with a maximum intensity of VIII.

An earthquake struck near the Hawaiian island of Lanai on February 19, at 10:11 pm HST with an estimated magnitude of 7.5 on the moment magnitude scale (Mw ). It remains one of the largest seismic event to hit the Hawaiian Islands since the 1868 Kaʻū earthquake, with its effects being felt throughout the entire archipelago. It caused severe damage on the islands of Lanai, Molokai and Maui. A tsunami may have been generated however there are speculations if it had actually happened. Despite the size of the quake and the extent of damage, there were no deaths.

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An earthquake occurred off the coast of the Alaska Peninsula on July 28, 2021, at 10:15 p.m. local time. The large megathrust earthquake had a moment magnitude of 8.2 according to the United States Geological Survey (USGS). A tsunami warning was issued by the National Oceanic and Atmospheric Administration (NOAA) but later cancelled. The mainshock was followed by a number of aftershocks, including three that were of magnitude 5.9, 6.1 and 6.9 respectively.

The 1870 Charlevoix earthquake occurred on 20 October in the Canadian province of Quebec. It had a moment magnitude of 6.6 Mw  and a Modified Mercalli intensity rating of X (Extreme). The town of Baie-Saint-Paul was seriously damaged by the event, with the loss of six lives. Effects from the earthquake were felt as far as Virginia and along the New England coast of the United States.

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″N78°05′13″W / 37.728°N 78.087°W / 37.728; -78.087

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