|Geophysicist Seth Stein, described in the Nature|
article as "a hyper-intelligent version of George Costanza,
the ever-complaining character from the television show
|USGS earthquake hazard map|
The implications are not trivial. Reinforcement of old buildings in this part of the country is an expensive proposition, and whether you have to reinforce for a magnitude 6.8 or magnitude 8.4 earthquake makes a huge difference in the cost.
Stein has written a trade-science book "Disaster Deferred: How New Science is Changing our view of Earthquake Hazards in the Midwest." It's a great read!