Reelfoot Rift

geological region, United States

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July 20, 2026

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The Reelfoot Rift is a geological region in the United States, primarily associated with the New Madrid Seismic Zone. This ancient rift extends for approximately 200 miles along the Mississippi River valley. It gained significant geological notoriety due to the tremendous New Madrid earthquakes that occurred in the winter of 1811–12. These powerful earthquakes caused land to sink, creating a depression that was filled by the Mississippi River, thus forming Reelfoot Lake in northwestern Tennessee. The rift's geological activity has shaped the landscape of the region, impacting areas in Tennessee, Missouri, and Illinois.12

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New Madrid earthquakes of 1811–12
Possible causes of the New Madrid earthquakes
…from activity occurring along the Reelfoot Rift, an ancient subterranean rift zone thought to have developed some 500 million years ago after geologic forces pulled the region in a northwest-southeast direction. Adherents to this hypothesis suggest that after hundreds of millions of years of relative inactivity, the pressure along the…
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…from activity occurring along the Reelfoot Rift, an ancient subterranean rift zone thought to have developed some 500 million years ago after geologic forces pulled the region in a northwest-southeast direction. Adherents to this hypothesis suggest that after hundreds of millions of years of relative inactivity, the pressure along the…
Read More