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Earthquake Called Significant for this Region

A 5.8 magnitude earthquake centered in Virginia about 80 miles from the nation’s capital caused reports of damage Tuesday afternoon.  It was felt across much of Pennsylvania.       The tremor chased people out of the state capitol complex and even buildings in Philadelphia and Pittsburgh. It was centered just outside of Louisa, Virginia.

 Dr. Charles Sharnberger, professor emeritus of earth sciences at Millersville University, says a quake of that magnitude is unusual in the mid-Atlantic region. He says it’s in an area called the central Virginia seismic zone that has been  known to have earthquakes over the decades, but not ones this big.

He says the aftershocks from this earthquake may go on for months. He says the largest ones are one step down from the main shock, but most will be in the magnitude 2 to 3 range.

In the Harrisburg area, Dr. Sharnberger says the earthquake  was apparently felt at an intensity of 3 to 5 on the 12 point scale, with 7 the beginning of damage.

As a precaution, PennDOT started inspecting bridges after the quake  on Tuesday that were at least 200 feet long or at least 60 feet high. They have been focusing on bridges that could be susceptible to earthquake damage.  They were not finding any problems.

The biggest earthquake in PA was a 5.2 magnitude in the Lake Erie region in 1998.    There was a 4.1 magnitude earthquake in the Lancaster Seismic Zone in 1984, and there was a 4.7 magnitude earthquake in Reading in 1994.  

 

**Map courtesy of the United States Geological Survey