The earthquake on Tuesday was the largest in Virginia in the Washington area since May 31, 1897, according to the U.S. Geological Survey. Reported damage from that quake was limited to “downed chimneys” and changes in the flow of spring water.
The epicenter of Tuesday’s earthquake was in Mineral, Va., roughly 84 miles from D.C. on an unnamed fault line.
A sudden release of energy from the earth’s crust causes the seismic activity known as earthquakes. The force of a quake is measured on the Richter scale, on which a lower number indicates less force.
Since 1977, there have been about 200 earthquakes in Virginia, according to a tally by Virginia Tech. The state is classified at “moderate” seismic risk because it is not located by any major fault lines and has a 10- to 20 percent chance of experiencing a 4.75 magnitude quake every century.
The most recent earthquake that originated in the state was a 3.6 magnitude that hit July 17, 2010.
A larger, 4.5-magnitude quake hit in 2003 and originated 28 miles west of Richmond. Six years earlier in 1997, a 2.5-magnitude quake occurred in Manassas.
The earliest recorded earthquake in Maryland was in Annapolis on April 24, 1758, and lasted 30 seconds, according to the U.S. Geological Survey.
The most recent quake in Maryland may have been the strongest recorded in the state’s history. At a 3.6 magnitude, it originated roughly 10 miles from Rockville in the early morning hours of July 16, 2010. – Hayley Peterson
