The Day the Mississippi River Flowed Backwards: The 1811-1812 New Madrid Earthquakes

Between December 1811 and February 1812, a series of powerful earthquakes struck the New Madrid Seismic Zone, centered around what is now New Madrid, Missouri. These earthquakes, among the most intense ever recorded in the contiguous United States, caused the Mississippi River to flow backwards temporarily, a phenomenon that remains one of the most extraordinary geological events in American history.

The first earthquake struck on December 16, 1811, with an estimated magnitude of 7.5 to 7.9. It was followed by two more major quakes on January 23 and February 7, 1812, both with magnitudes above 7.0. The series of quakes and aftershocks were felt as far away as the East Coast, with reports of buildings shaking in cities like Washington, D.C., and Charleston, South Carolina.

The quakes caused massive ground deformations, including the creation of Reelfoot Lake in Tennessee and large areas of land being uplifted or subsiding. One of the most dramatic effects was the temporary reversal of the Mississippi River’s flow. The uplift of the riverbed caused a surge of water to flow upstream, creating waterfalls and waves that were reported by witnesses at the time.

The earthquakes caused widespread destruction in the sparsely populated region, toppling trees, destroying settlements, and changing the landscape. The town of New Madrid was heavily damaged, and many areas were left permanently altered. Fortunately, due to the low population density, the death toll was relatively low compared to the potential damage such quakes could cause today.

The New Madrid earthquakes highlight the dynamic and unpredictable nature of the Earth’s crust. They serve as a reminder of the seismic risks that still exist in the central United States, prompting ongoing research and preparedness efforts to mitigate the impact of future quakes in the region.