Arkansas isn’t normally linked with earthquakes, yet the state has had some of the most violent and deadly seismic occurrences in North American history. The most infamous of them occurred in the early 1800s within the New Madrid seismic zone, a fault system that runs from Illinois to Arkansas.
These earthquakes were so powerful that they changed the topography, formed new lakes and islands, and even caused the Mississippi River to flow backward for a moment.
The New Madrid Earthquake of 1811-1812
The New Madrid earthquakes were four large shocks that struck between December 16, 1811, and February 7, 1812. The first, on December 16, 1811, had a magnitude ranging from 7.0 to 8.0 and was felt as far away as New England and Canada. It startled northeastern Arkansas citizens awoke at about 2:15 a.m., causing significant damage to buildings, highways, and bridges.
The earthquake also caused landslides, cracks, and liquefaction, a condition in which soil loses firmness and acts like a liquid. This caused the ground to sink, fracture, and bubble, resulting in enormous expanses of marshland.
The second earthquake, on January 23, 1812, had a little lower magnitude of 7.0 to 7.5 but caused significant damage and fear. It was followed by hundreds of aftershocks, some of which were severe enough to be felt in faraway places. The third earthquake, on February 7, 1812, was the most violent and deadly of the sequence, measuring 7.5 to 8.0. It struck at New Madrid, Missouri, and was felt over the eastern portion of the United States.
It made the most dramatic alterations to the environment, generating Reelfoot Lake in Tennessee, causing sandblasts and sand boils, and momentarily reversing the flow of the Mississippi River. The fourth and last earthquake occurred on March 27, 1812, with a magnitude of 6.5 to 7.0 and centered in Little Prairie, Missouri. It was less devastating than the previous ones, but it nonetheless instilled widespread dread and concern among the public.
Impact and Legacy of the New Madrid Earthquake
The New Madrid earthquakes were among the most severe natural disasters in US history. They impacted an area of approximately 600,000 square kilometers and were felt by an estimated 10 million individuals. They caused considerable property and infrastructural destruction, as well as disruptions in the lives and livelihoods of thousands of settlers, Native Americans, and enslaved people.
They also had a significant effect on the region’s culture, politics, and religious beliefs. Some perceived the earthquakes as a sign of divine anger or judgment, while others saw them as a warning of the end of the world. Some individuals suspected that the earthquakes were caused by human activity, such as the War of 1812, the Louisiana Purchase, or Tecumseh’s War.
The earthquakes in New Madrid also had long-term consequences for the region’s geology and ecosystem. They formed new features such as lakes, islands, sandbars, and hills, as well as changed the path of rivers and streams. They also had an impact on the local flora and fauna, resulting in the formation of new habitats and niches for different species.
Scientists and historians can study some of the changes generated by the earthquakes that remain observable today. The New Madrid seismic zone remains active, posing a hazard to the region’s contemporary population and infrastructure. According to some calculations, there is a 7-10% probability that another earthquake of magnitude 7.0 or larger may occur within the next 50 years.
Conclusion
The New Madrid earthquakes of 1811-1812 in Arkansas were among the most violent in North American history, changing the terrain, creating new features, and temporarily reversing the Mississippi River’s course. The seismic occurrences had a long-term influence on the region’s culture, geology, and environment, influencing its history and offering vital insights to scientists. The New Madrid seismic zone remains active, highlighting the area’s continuous seismic vulnerability.