The Earth Moves on the East Coast

A rare trembler centered in Virginia yesterday rattled nerves up and down the East Coast.  The 5.8 earthquake frightened many people who've never experienced a quake and caused a fair share of good-natured ribbing from those of us who have, when we heard about colleagues fleeing into the streets in Washington, DC. But how serious was yesterday's quake, and what about the others that followed in Colorado and northern California? Writer-journalist Simon Winchester is author of A Crack in the Edge of the World: America and the Great California Earthquake of 1906.