Madrid Fault Line or The Day The Mississippi River ran Backwards 

Thanks for posting this link. I read it and was amazed. About a year ago, I read a book called "Crack in the World" about the early 1900s quake in San Fransisco - which mentioned a small amount about the Madrid fault line. I had no idea that these faults were still so active - until the quake of late August 2011 which cracked the Washington Monument and knocked stones from the Washington Cathedral. (link)

It would be interesting to know what is 'happening' with the hot springs in Yellowstone park. These springs are 'linked' to plate activity. Some scientists believe that changed activity in these springs/geysers is an indication that 'something is brewing'.

Here's another article on the subject: link