Below is some of the better info I found online. this was from all places a weather site in Ireland (its small world). Also there is a very good video.
One of the strongest earthquakes to strike the U.S. East Coast in decades rocked buildings as far as North Carolina and Canada on early Tuesday afternoon, seismologists said, causing damage to buildings and a number of injuries.
The 5.8-magnitude earthquake at 1.51 p.m. local time (1751 GMT) was centered about 5 miles (8 kilometers) south-southwest of Mineral, a small town in Louisa County in Virginia. It struck about 3.7 miles (6 kilometer) deep, making it a very shallow earthquake and also the most powerful earthquake in the State’s history, according to the United States Geological Survey (USGS). The quake was followed early Wednesday by two aftershocks, measuring 4.2 and 3.0 magnitude on the Richter Scale
The USGS said 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 Central Virginia Seismic Zone has produced small and moderate earthquakes since at least the 18th century. The previous largest historical shock from the Central Virginia Seismic Zone occurred in 1875. The 1875 shock occurred before the invention of effective seismographs, but the felt area of the shock suggests that it had a magnitude of about 4.8. The 1875 earthquake shook bricks from chimneys, broke plaster and windows, and overturned furniture at several locations. A magnitude 4.5 earthquake on 2003, December 9, also produced minor damage.
The extent of the damage near the epicenter of the earthquake was not immediately clear, and Virginia Governor Bob McDonnell said all resources of the state have been put on alert to assist in any way necessary. “All indications are that emergency response plans and orderly evacuations have gone well today, and I thank all involved,” he said.
Photos and videos uploaded to social networking websites showed damage to some buildings. A video uploaded to YouTube showed debris which crushed destroyed several cars in Tyson’s Corner, a unincorporated census-designated place in Fairfax County, Virginia.
At Louisa High School, not far from the epicenter, six students and one staff member were injured. One of them, a teacher, suffered minor injuries when a bookcase toppled over onto her. It was not immediately clear how the students were injured.
At the North Anna nuclear power plant in central Virginia, officials declared an Alert, which is the second-lowest of the four emergency classifications. The alert was declared after the plant lost electricity from the grid following the earthquake, but onsite diesel generators and the plant’s safety systems were operating normally.
At the Surry Nuclear Power Plant, plant officials declared an Unusual Event, which indicates a potential decrease in plant safety but is lower than an Alert.
WASHINGTON, D.C.
Most buildings in downtown Washington, D.C. were immediately evacuated after the earthquake, including the White House, the Pentagon, the U.S. Capitol, and other government buildings. Several people were injured.
Pete Piringer, a spokesman for the D.C. Fire and Emergency Medical Services (EMS), said the most significant damage was reported at the Ecuadorian Embassy, Bell Multicultural School, and several other buildings. “Most of those have significant cracks in the building, chimneys fallen down in the street, things of that nature,” the spokesman said.
“As you might imagine, our crews are very busy but those who are not on call are out in various neighborhoods doing some assessments,” Piringer said. “Checking for structural damage, of course our primary focus will be hospitals, senior centers, schools, buildings of that nature will have the priority, and they are reporting some damage to some of those buildings.”
NEW YORK
In the state of New York, Governor Andrew Cuomo said there were no reports of damage to buildings, bridges, roads, power grids, the Indian Point nuclear power plant, or other infrastructure. “The State Office of Emergency Management continues to monitor effects in New York State from the earthquake,” he said.
In New York City, scores of buildings were also evacuated, including City Hall and the 26-story federal courthouse which is located in lower Manhattan. “Shortly before 2:00 PM, we evacuated City Hall briefly, but quickly returned to work,” Mayor Michael Bloomberg said.
Bloomberg said the earthquake was felt across the city’s five boroughs. “I’ve spoken with our Police and Fire Commissioners, and we’ve activated the Office of Emergency Management’s Situation Room and spoken to other city agencies, including the Department of Buildings. Thankfully, there are no reports of significant damage or injuries in New York City at this time,” he added.
Scott Vanderhoef, County Executive of Rockland County, where the Indian Point nuclear power plant is located, said the earthquake was felt at several locations around the plant, but not inside the control room. “Both units are operating at full power. There are no issues affecting plant operation. Both units have entered the procedure for responding to a seismic event and are checking equipment around the plant,” he said.
Vanderhoef added that there were also no reports of damage elsewhere in the county.
MASSACHUSETTS
The earthquake was also felt on the island of Martha’s Vineyard, located off the coast of Massachusetts, where U.S. President Barack Obama is for his annual vacation. “The president didn’t feel the earthquake today,” White House Principal Deputy Press Secretary Josh Earnest said.
Less than an hour after the earthquake, Obama held a conference call with a number of senior government officials to discuss the event. “The President was told that there are no initial reports of major infrastructure damage, including at airports and nuclear facilities and that there were currently no requests for assistance. The President asked for regular updates on the situation,” Earnest said.
PENNSYLVANIA
Shaking could also be felt in large parts of Pennsylvania, and Pennsylvania Department of Transportation bridge inspectors were doing precautionary inspections of bridges. “We have no reason to believe the Virginia earthquake caused major damage to any state roadways or bridges,” said Scott Christie, the Department’s Deputy Secretary for Highway Administration.
The department said it was first inspecting bridges which are at least 200-feet (60-meter) long or 60 feet (18 meters) high. Inspections would continue throughout the evening and on Wednesday.
In Berks County, however, police closed the Penn Street Bridge in Reading after noticing cracks in the pavement on the bridge approach but the cracks may have been there before the earthquake. “PennDOT inspectors will thoroughly assess the bridge to make sure it was not damaged,” the department said.
Unusual Events were declared at the Peach Bottom Nuclear Generating Station, the Three Mile Island Nuclear Generating Station, the Susquehanna Steam Electric Station, and the Limerick Nuclear Power Plant.
WEST VIRGINIA
West Virginia Governor Earl Ray Tomblin said he was ‘surprised and immediately concerned’ about the earthquake. “Within minutes of the event, I directed Homeland Security Director Jimmy Gianato to contact various state agencies, utilities, chemical plants and the U.S. Army Corps of Engineers to assess and make quick determination if any of our citizens or significant infrastructure was in need of assistance,” he said. “Fortunately, there are no reports of any injuries or damage caused by the quake.”
NEW JERSEY
Plant officials declared Unusual Events at the Salem Nuclear Power Plant, the Hope Creek Nuclear Generating Station, and the Oyster Creek Nuclear Generating Station.
MARYLAND
An Unusual Event was declared at the Calvert Cliffs Nuclear Power Plant near Lusby in Calvert County.
NORTH CAROLINA
An Unusual Event was declared at Shearon Harris Nuclear Power Plant in New Hill.
MICHIGAN
An Unusual Event was declared at Donald C. Cook Nuclear Generating Station north of Bridgman.
The earthquake in Virginia was the state’s largest in intensity since a 5.9-magnitude earthquake struck Giles County in 1897. It also came just hours after a 5.3-magnitude earthquake struck 4 miles (6 kilometers) south of Segundo, a small unincorporated community in Las Animas County, Colorado. There was some damage, and the USGS said it was the strongest earthquake to hit the state since a 5.3-magnitude earthquake was recorded near Denver on August 9, 1967.
MORE ABOUT THE EAST COAST’S SEISMIC PAST
Previous seismicity in the Central Virginia Seismic Zone has not been causally associated with mapped geologic faults. Previous, smaller, instrumentally recorded earthquakes from the Central Virginia Seismic Zone have had shallow focal depths (average depth about 8 km). They have had diverse focal mechanisms and have occurred over an area with length and width of about 120 km, rather than being aligned in a pattern that might suggest that they occurred on a single causative fault. Individual earthquakes within the Central Virginia Seismic Zone occur as the result of slip on faults that are much smaller than the overall dimensions of the zone. The dimensions of the individual fault that produced the 2011 August 23 earthquake will not be known until longer-term studies are done, but other earthquakes of similar magnitude typically involve slippage along fault segments that are 5 – 15 km long.
Earthquakes in the central and eastern U.S., although less frequent than in the western U.S., are typically felt over a much broader region. East of the Rockies, an earthquake can be felt over an area as much as ten times larger than a similar magnitude earthquake on the west coast. A magnitude 4.0 eastern U.S. earthquake typically can be felt at many places as far as 100 km (60 mi) from where it occurred, and it infrequently causes damage near its source. A magnitude 5.5 eastern U.S. earthquake usually can be felt as far as 500 km (300 mi) from where it occurred, and sometimes causes damage as far away as 40 km (25 mi).
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