April 21, 2010
Seismic experts have calculated that the city of Concepcion, Chile, was displaced by a distance of three meters (about ten feet) toward the west as a result of the massive February 27 earthquake. This is going to cause big headaches for cartographers, GIS users, landowners, lawyers, etc. See latercera.com; hat tip to Angela Nebel.
On a more serious note, this year must be setting a record for the number of major earthquakes and even volcanoes around the world, and three have been recorded this month alone. Here's a quick, unofficial list: