They created two of America's most famous duck hunting holes, and are considered, as a whole, one of the most significant seismological events in modern time, yet the New Madrid earthquakes will always remain somewhat of a mystery.
In a sense, the series of earthquakes, occurring from Dec. 1811 through Feb. 1812, was one massive duck habitat-improvement project.
In the World Almanac's list of major earthquakes, which runs as far back in time to 526 A.D., only the New Madrid event has no estimated deaths attributed to it.
One study indicated only one person could be definitely confirmed as having died on land during the series of quakes: "... that one was a woman who ran until exhausted and died of fright." Other unconfirmed reports said several people drowned during the upheavals in the Mississippi River.
If there were such a thing as the perfect place for an earthquake, the sparsely-inhabited Great Swamp along the Mississippi River in the early 1800s was it. Falling chimneys posed the biggest danger to the few people living there.
It's been said the Mississippi River flowed backward as the water rushed to fill depressions left by the quakes.
Two of the biggest depressions became Reelfoot Lake in western Tennessee and Big Lake in northeast Arkansas, both of which would soon be major gathering points for sportsmen, market-hunters and duck call makers.
A section of the St. Francis River also was affected. A 1904 account describes Lake St. Francis and the Hatchie Coon Sunk Lands as a 40-mile-long lake averaging a half-mile in width. Modern geological studies have located an earthquake-related depression and uplift in the St. Francis River channel that probably created the lake.
The series of tremors that shook this area beginning in 1811 is now estimated to have included at least three "great earthquakes," with a magnitude greater than 8.0 on the Richter Scale, plus hundreds of lesser tremors.
One eyewitness account included the following:
The morning of December 15, 1811, was cloudy and a dense fog prevailed, and toward nightfall the heavens showed signs of distress. On the following morning, the 16th, about 5 o'clock a.m., we felt the shock of an earthquake, accompanied by a rumbling noise resembling the distant firing of a cannon, which was followed in a few minutes by the complete saturation of the atmosphere with sulphurous vapor. The moon was shining brilliantly, but the sulphurous vapor caused the earth to be wrapped in absolute darkness. The wailing inhabitants, the stampede of the fowls and beasts, the noise of falling timber, the roaring of the Mississippi, the current of which was retrograde for a few minutes — formed a scene too appalling to conceive of.
The New Madrid Seismic Zone remains a source of anxiety today. Another event of this magnitude would be catastrophic for many cities and towns, among them Memphis and St. Louis, which have sprawled since the Great Swamp was conquered.