I'll have to email that link to HW (or Holler over to the next room); she is part of a team working on intraplate quakes in China with some comparison to New Madrid. We had a bit of a debate on this a few months or year ago on this page with John V. Let's put it this way: I live in central Missouri and we chose to not get earthquake insurance. I think the U.S. hazard maps over-rate New Madrid zone. GPS shows no significant motion of the blocks at some distance from the zone, so it is hard to reload the faults. There is some minor motion closer to the faults, but that could still be adjustment after the 1811-1812 quakes.

But, there is a fair amount of evidence from sandblows etc that something has been firing off every 500(?) years or so. I'm curious whether it has to be the New Madrid zone, or if there are quakes off to the west or east.

Chris