August 24th, 2011

Earthquake in Virginia, United States

Posted at 12:27 PM ET

virginia-quake-smallA strong and rare earthquake hit the state of Virginia in the United States at 17:51 UTC on August 23 (13:51 local time), shaking a wide area of the U.S. East Coast and prompting the evacuation of buildings in New York and Washington D.C. The event, measuring 5.8 Mw, was located 5 miles (8 kilometers) south-southwest of Mineral and 38 miles (61 kilometers) northwest of Richmond in central Virginia. It was also centered a shallow 3.7 miles (6 kilometers) underground, according to the U.S. Geological Survey (USGS). According to the USGS, around 2.4 million people live in areas impacted by a Modified Mercalli Intensity (MMI) of V or higher. The town of Louisa (population of 2,000) experienced intensity VII on the MMI scale, equivalent to severe shaking with the potential to cause heavy damage to vulnerable structures and moderate/heavy damage to more resistant structures. Elsewhere, Newington (21,000), Hybla Valley (17,000) and Fort Hunt (13,000) were hit by MMI intensity V, moderate shaking that can cause light structural damage. At least four aftershocks have been recorded.

The USGS said the earthquake was one of the most powerful to hit the U.S. East Coast since 1897. Reports said the earthquake was felt as far as Boston, Massachusetts, to the north and Charleston, South Carolina, to the south. More than 12 million people live close enough to the earthquake’s epicenter to have felt the shaking, the USGS said. Numerous injuries were reported but no deaths or serious injuries occurred. The Pentagon, White House and U.S. Capitol were evacuated in Washington, and thousands of workers poured onto the streets in New York and other cities along the east coast as the shaking caused office buildings to sway. However, there were no reports of extensive damage from the earthquake and EQECAT estimate insured losses will be less than USD100 million.


Hazard data illustrated in the CAT-i map was taken from i-aXs®, Guy Carpenter’s web-based risk management platform. i-aXs users can view impacted areas on any map as well as see how their portfolios were affected. Please contact your broker or GC Analytics (SM) representative for assistance or go to for further information.

Pockets of damage have been reported in communities close to the epicenter region in Virginia. Reports of cracked walls, contents damage, fallen ceiling titles and damaged plaster have been recorded in Louisa County and other nearby communities. Officials have also reported damage to several school buildings and town hall buildings in the county. Several historical monuments sustained more serious damage as such unreinforced buildings were less able to resist the shaking. Reports said at least four historic buildings in the town of Culpeper were seriously damaged and more than a dozen others had structural and cosmetic damage. Washington D.C.’s National Cathedral suffered damage with three spires in the central tower breaking off. The Washington Monument and the Smithsonian Castle were closed after cracks were found in the walls of the buildings. The embassy of Ecuador was also reported to have suffered major damage.

Infrastructure and communications networks in the region also escaped major damage, according to reports. Although the earthquake did trigger an automatic shutdown of the Dominion Resources’ North Anna nuclear power station in Virginia, power was quickly restored to the plant and no significant damage occurred. No extensive power cuts were reported elsewhere. Transportation in the region was disrupted by the earthquake, however. Speed restrictions were imposed on train services between Washington and Baltimore as inspections of the rail infrastructure was carried out. Flights from several airports in the region, including John F. Kennedy and Newark in New York and Reagan in Washington D.C., were also delayed as authorities checked for damage.

According to EQECAT, insured losses from the earthquake are expected to be less than USD100 million. EQECAT said an earthquake of this magnitude in central and eastern regions of the U.S. generally does not produce an expectation of widespread catastrophic damage as most modern structures are built to withstand such shaking. It added that had the earthquake been a magnitude 7 instead of a roughly magnitude 6 temblor, insured losses would have been close to USD2 billion.

Table 1: Estimated Population Exposed to Significant Earthquake Shaking

Estimated MMI

Estimated Population Exposure

Perceived Shaking






Very strong







Sources: USGS, WSI, Reuters News, Associated News, Agence France Presse, CNN News, BBC News, EQECAT

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Guy Carpenter publishes CAT-i reports for major natural catastrophes worldwide. These reports cover catastrophes including worldwide tropical cyclones, earthquakes, major UK and European floods and any other natural event that is likely to incur a significant loss to the (re)insurance industry. Please email if you wish to be added to the free email distribution list.

Guy Carpenter compiles RISK-i reports for major technological or man-made events worldwide. These reports cover risks to property, transport and life including explosions, fires, crashes, engineering disasters and terrorist attacks that are likely to incur a significant loss to the (re)insurance industry. Please email if you wish to be added to the free email distribution list.

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