Despite the many hypothesis about the New Madrid, Missouri earthquake a notable theory is that the earthquakes arose 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.
Implying that after hundreds of millions of years of relative inactivity, the pressure along the faults had again built up from the east-west compression of the North American Plate leading to the earthquake.
