Virginia Earthquake - August 23, 2011

Some very unique shaking, rattling and rolling hit us today!  It was not the first earthquake I've ever felt, but at 5.9 on the richter scale is was very much so the strongest.  Thought this was an interesting piece post by USA TODAY's Dan Vergano:

"Central Virginia does get its share of minor earthquakes, but an earthquake of this size on the East Coast is certainly very unusual," says seismologist Karen Fischer of Brown University.

Virginia is not on an active earthquake fault and is roughly in the middle of the North American continental crustal plate, she says. But it has residual fault scars left over from 200 to 300 million years ago, when it was an earthquake zone, at the time when the Atlantic Ocean rifted apart from Europe. "We are just seeing pressure build up and release on those scars," Fischer says. "There is a lot of debate on exactly what is going on down there and exactly how quakes this big happen in this kind of crustal zone."

Because the crust under the East Coast is colder and firmer than the West Coast, shocks travel more efficiently through it, accounting for the widely felt shaking.

"One lesson of this quake is that building codes will likely need to be revisited on the East Coast," Fischer says. "Because we are not as conscious of earthquakes here as the West Coast and we will have to see about structural damage to buildings, although I have not heard any damage reports so far."