OK, this has nothing to do with cognitive science, but today’s quake felt throughout the southeast reminded me of a little history that some people may not be aware of. In Tennessee, there is only one large natural lake, Reelfoot Lake, in the far western part of the state just south of Kentucky, near the Mississippi River. It’s an exceptionally beautiful place, with bald eagles and bald cypress trees (in the picture below), but what’s really cool about it is how it was formed.

In 1811 and 1812, there were dozens of earthquakes, including 4 very large ones, in thea area around west Tennessee, southwest Kentucky, Missouri, Arkansas, and southern Illinois, culminating in the New Madrid earthquake on February 7, 1812, which is thought to have been the strongest earthquake in the continental United States since Europeans settled here. Legend has it that this earthquake was so strong that it caused the mighty Mississippi River to flow backwards. Water overflowed the banks, and formed Reelfoot Lake. This is the story that everyone learns growing up in Tennessee, and that the park rangers tell you when you visit the lake. Sure, it’s unlikely that the Mississippi actually flowed backwards, but the earthquakes did radically change the landscape over a very short period of time, causing water to flow into what is now the lake. When water levels drop, you can see the tree stumps from the forest that, before the quakes, had occupied the area.

The scary thing is that scientists have been saying for years that the New Madrid fault is due for another big quake. In 1811-1812, the region was sparesly populated, and while there aren’t good figures, the damage was minor relative to the size of the quakes. Can you imagine, though, what would happen to a city like Memphis if a quake that measured 8.0 on the Richter scale occurred just to the north?