I have been following this thread daily since the first post. First off, I have to say thank you to Robin Marks for your research and dedication to this thread; and Puterman for all that he contributes as well. Also to Susan Frey for her continued updates and up to the minute reports from Arkansas.
Robin, I dont know if tonight was the first showing of this or not but as I was flipping channels, I stopped on National Geographic and they were
showing a 2011 documentary called "Countdown to Catastrophe: Megaquake". The minute I began watching (about 60 minutes ago), they were discussing
the quake swarms in Arkansas and the New Madrid Fault and that the fault seems to be getting re-activated. They talked about this fault being due
for a big quake. Also.......I could not help but think of this thread as they interviewed people who said that memphis is basically "sitting on a
spring ready to release". They talked about liquification, the rift, sandblasts from the big quake of 1811 and 1812 and that this area of the
country is one of the weakest points of the country.
This Nat Geo documentary seems to agree with your theory about Memphis being one possible location likely for a big quake. The documentary also
talked about their theory that seattle area may be the most likely place in the US for a megaquake.
(This is my first post ever. I'm still learning my way with this so please go easy on me if I haven't posted perfectly)