Tuesday, August 23, 2011

Moderate earthquakes hit Virginia AND Colorado

Monday night an earthquake of 5.8 Richter scale strength hit southern Colorado in the area of the border with New Mexico, Monday, August 22, 2011, evening. It was the largest quake to hit Colorado in more than a century.

Receiving much more media attention was the earthquake to hit Mineral, Virginia today, August 23, at about 1:00 PM in the center of the state. Mineral, the epicenter town, is midway between Charlottesville and Fredericksburg, fifty miles from Richmond. In media reports it has been identified as the Washington, D.C. earthquake. It was reported as being a 5.9 scale earthquake. This would be the strongest earthquake in the Mid-Atlantic region in decades. It exceeds a 2003 central Virginia earthquake of 4.5, and the 1998 Pymatuning earthquake in northeast Pennsylvania, with a 5.2 reading.

This second earthquake has been reported felt as far as Toronto, Ontario; Detroit, Michigan; North Carolina and Massachusetts. Source: "5.9 earthquake in Virginia shakes East Coast, rattles Michigan office buildings," "Detroit Free Press."

Wonder how people in the Maryland/DC/Virginia area feel about the relatively old nuclear power plants in eastern Virginia and southern Maryland: Calvert Cliffs (operative since 1975) in Maryland on the Chesapeake Bay, North Anna Nuclear Generating Station (operative since 1978), near Charlottesville, Virginia and Surry Nuclear Power Plant (operative since 1972) in the Norfolk/Virginia Beach, Virginia vicinity.

The wikipedia article for the Virginia Seismic Zone reports that there have been several quakes in the past decade in the area, albeit with mild readings, around 3.6. Just over the Potomac River lies the site of the 2010 Germantown, Maryland earthquake (the Potomac-Shenandoah Earthquake, as labeled by Wikipedia), 3.6 on the Richter Scale. The North Anna plant is sited precisely in the Virginia Seismic Zone.

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