Been spending the last day or so listening to documentaries on the New Madrid fault line. Pretty fascinating subject for a history/science fan like me. In case you hadn't heard much about it. In 1811 and 1812, massive earthquakes rocked New Madrid, MO resulting in sulfuric gas clouds, the collapse of buildings, huge fissures up and down and laterally and the Mississippi River flowing the opposite direction. It was felt as far away as Boston, MA where it rang church bells. After the initial quake, the zone remained active for well over a year with aftershocks being felt regularly. There are many accounts from the time frame, including those described by Davy Crockett in his book where he navigated some of the fissures in his journeys. Geologists surveying the area in the years after found older evidence of fissures. Indicating this zone has been active for some time. Even today, the fields that were created post 1811 to support the mid-America farming boom experience "sand blows" such as this one. Essentially a weak spot in bedrock that pushes gases up through the soil creating a mini sand volcano. The 1811-1812 quakes were largely buried by history despite there still being smaller quake events since that time. The main concern being, cities like Memphis being built afterwards with no regard to the potential of future events. It wasn't mentioned, but I couldn't help but wonder if it was somehow tied to the ancient "ring of fire" that encompasses the continued geothermal activity in Arkansas...even stretching further south to extinct volcanoes under Jackson, MS. Anyway, something interesting to ponder today.