The magnitude 5.8 quake that struck central Virginia yesterday was felt from Florida, to Maine to Missouri. “This is probably the most widely felt quake in American history, even though it was less than a 6.0,” says Michael Blanpied, a USGS seismologist DISCOVER contacted today.
The reason for this intensity is that the East Coast, like the controversial New Madrid Seismic Zone in the central U.S., is located in amidst old faults and cold rocks in the middle of the North American tectonic plate. This is very different than far more common quakes plaguing coastal zones like California, caused by the constantly shifting outskirts of the continent’s plate. “Earthquake hazard is particularly high in the eastern and central U.S. because seismic waves travel so efficiently through the old, cold rocks in the middle of the plate, and that shaking carries very far,” says Blanpied. “Earthquakes in these zones are infrequent, but when they do occur, they shake such a large area, and so many people, it raises their importance.”
