USA: Virginia quake deals a seismic surprise

Lack of monitoring in the region poses a challenge to those trying to understand the once-in-a-century event, reports Richard Monastersky for Nature. He reports that "Geophysicists are now debating how to interpret the absence of evident ongoing deformation in the New Madrid Seismic Zone. Stein, [a geophysicist at Northwestern University in Evanston, Illinois] argues that the risk of large earthquakes there is minimal, a view at odds with that of the USGS and of many other researchers" interviewed.