In the theory of plate tectonics, the earth's outermost layer is composed of plates that move relative to each other. Most of the world's earthquakes occur at the plate boundaries. Since places like the California coast are on a boundary between two plates, they have many more earthquakes than places like Virginia, which is near the center of the North American plate. Yet earthquakes still occur in Virginia.

Virginia has had over 160 earthquakes since 1977 of which 16% were felt. This equates to an average of one earthquake occurring every month with two felt each year. Click here for a summary of the largest earthquakes in Virginia.

Until the magnitude 5.8 earthquake in 2011, the largest earthquake to occur in Virginia was the 1897 magnitude 5.8 Giles County earthquake. This earthquake is the third largest in the eastern US in the last 200 years and was felt in twelve states.

Seismic activity (seismicity) has been known for several decades to be strongest in and around Giles County and in central Virginia. This led researchers at the VTSO to concentrate seismic monitoring stations in these two areas, as shown below, which shows earthquakes (circles, scaled to) in and near Virginia from 1774 through 1994.

The 2011 Virginia earthquake was a magnitude 5.8 earthquake in the U.S. state of Virginia on August 23, 2011, at 1:51 PM EDT. The focus was 37 mies northwest of Richmond and 5 miles from the town of Mineral, Virginia. The earthquake was along the Spotsylvania Fault, an ancient fault line that now sits in the middle of the North American plate. Four aftershocks happened within twelve hours of the main earthquake. The aftershocks had magnitudes 2.8, 2.2, 4.2 and 3.4. About 35 hours after the main earthquake, a sixth aftershock of magnitude 4.5 occurred.

In Washington, D.C., the White House, the Capitol building and other buildings were evacuated. In Arlington County, Virginia, a pipe in the Pentagon broke. The pipe flooded two corridors. Other buildings were evacuated in Philadelphia, Boston and New York City.

Buildings in the Washington, D.C. area were damaged, but not severely. The quake damaged three of the Washington National Cathedral's four pinnacles (corner spires) and cracked some of the Episcopal church's flying buttresses. However, buttresses that support the central tower, a prominent part of the city skyline, look normal. The National Park Service found cracks near the top of the Washington Monument. The monument is closed indefinitely. The earthquake knocked off four of the six spires atop the Washington D.C. Temple of The Church of Jesus Christ of Latter-day Saints. The pieces fell to the ground along with several pieces of marble from the temple's outside wall.

It is estimated that approximately one-third of the U.S. population might have felt the earthquake, more than any other earthquake in U.S. history