The New Madrid earthquake was a series of powerful earthquakes that occurred in the central United States, near the town of New Madrid, Missouri, between December 1811 and February 1812. The earthquakes caused widespread damage, altered the course of the Mississippi River, and were felt as far away as Canada and the East Coast. The earthquakes are estimated to have had magnitudes ranging from 7.0 to 7.5 on the Richter scale, making them some of the largest in U.S. [history](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[1](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[2](https://www.usgs.gov/programs/earthquake-hazards/science/summary-1811-1812-new-madrid-earthquakes-sequence)
The earthquakes were caused by the movement of the North American Plate along the Reelfoot Rift, a buried fault zone that extends from southern Illinois to northeastern Arkansas. The rift is a failed continental rift that formed about 750 million years ago, when the continent began to split apart. [The rift was reactivated by the stresses of the plate tectonics, resulting in the release of enormous amounts of energy along the fault](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[3](https://www.britannica.com/event/New-Madrid-earthquakes-of-1811-1812)[4](https://missouriencyclopedia.org/events/new-madrid-earthquakes-1811-1812)
The earthquakes had significant effects on the landscape and the people of the region. The ground shook violently, creating large fissures, sand blows, landslides, and subsidence. The Mississippi River changed its course, creating new islands, lakes, and channels. Some eyewitnesses reported that the river flowed backward for a short time. The earthquakes also triggered the formation of Reelfoot Lake in Tennessee, by damming up a section of the river.
The earthquakes were also felt by the Native Americans and the European settlers in the area, who interpreted them in different ways. Some Native Americans, such as the Shawnee leader Tecumseh, saw the earthquakes as a sign of their god’s wrath and a confirmation of their resistance to the white encroachment. Some European settlers, on the other hand, saw the earthquakes as a divine punishment for their sins and a call for repentance. The earthquakes also affected the social and economic life of the region, as many people fled, relocated, or rebuilt their homes and communities.
The New Madrid earthquakes remain a subject of scientific interest and public concern, as the potential for future large earthquakes in the region is still high. The U.S. Geological Survey estimates that there is a 7 to 10 percent chance of a magnitude 7.5 or greater earthquake occurring in the New Madrid Seismic Zone in the next 50 years, and a 25 to 40 percent chance of a magnitude 6.0 or greater earthquake. Such an event could cause significant damage and casualties in the densely populated areas of the Midwest and the South.
[](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[1](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes): [](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[2](https://www.usgs.gov/programs/earthquake-hazards/science/summary-1811-1812-new-madrid-earthquakes-sequence): [](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[3](https://www.britannica.com/event/New-Madrid-earthquakes-of-1811-1812): [](https://en.wikipedia.org/wiki/1811%E2%80%931812_New_Madrid_earthquakes)[4](https://missouriencyclopedia.org/events/new-madrid-earthquakes-1811-1812): : [5] : [6] : [7] : [8] : [9] : [10]