USGS site has this link posted:
newmadrid2011.org...
Interesting in context OP, especially with MC243 making news. "...great 1811 and 1812 New Madrid earthquakes that forever changed the mid-western
landscape. These quakes were felt across the U.S. and as far south as the Gulf of Mexico, and as far north as Canada...."
MC243 related:
www.nola.com...
(Unconfirmed as of posting).
Global Incident map (
quakes.globalincidentmap.com...) gives nice graphic to fuel speculations. Go back to the date 9.1 Japan event and note that
the US tremor activity has been spreading east since then.