Virgina has been hit by a 5.9 earthquake a few minutes ago. The worst in at least 30 years anywhere in a 1000km distance. It is perhaps a testament to the fact that I’m not an American, that I immediately thought about the New Madrid Earthquake before remembering that Virginia, as one of the original colonies, was along the coast. (New Madrid is in fact smack in the middle of the USA, not along the coast. It caused the Mississippi to flow backwards at some point.)
Just to put the quake into perspective – New Madrid was struck by a quake at least 100 times as powerful (with estimates going as high as 1000). It has been about 200 years since that earthquake – one shudders to imagine what will happen to this woefully unprepared area when it repeats.
What does a factor of 1000 mean in terms of earthquake magnitudes? It is the difference between a mag 5.9 and a mag 7.9 earthquake. (The recent Tohoku Earthquake was a mag 9.0 – about 30.000 times as powerful as the Virgina one.)