The New Madrid Earthquakes of 1811–12

The New Madrid earthquakes of 1811–12, were three large earthquakes that happened near New Madrid, Missouri, from December 1811 to February 1812. There were thousands of aftershocks, about 1,874 of them were so large that they could be felt as far as Louisville, Kentucky, almost 190 miles away. It is unknown how many lives were lost during the earthquakes; however, scholars say that the number probably wasn’t very large. The region that the quakes affected had a small population. The main shock happened around 2:15 in the morning on December 16th in 1811.

It happened because of movement along the Cottonwood Grove Fault in Arkansas. It was then followed by three large aftershocks with magnitudes that ranged from 6.0 to 7.0 that occurred throughout the the following 48 hours. Even though the tremors were so strong, only minor damage was reported to human-made structures. Including collapsing chimneys, falling trees, and cracking timbers in houses. A few areas sank, while others were lifted. Soil liquefaction caused large sand blows that destroyed farmland in states such as Missouri, Tennessee, and Arkansas. Because rocks in the eastern United States have few active faults to interrupt the propagation of seismic waves, ground vibrations from earthquakes generated in the region can travel up to thousands of miles.

Eyewitnesses noted that the shaking rang church bells as far away as Boston, Massachusetts, and brought down chimneys in Cincinnati, Ohio, about 360 miles away. A quake with a magnitude of 7.0 was the strongest one that day and became known as the “dawn aftershock” that occurred at 7:15 a.m. The second quake occurred on January 23 and was the smallest of the three earthquakes. The main shock happened at 9:15 in the morning, its estimated magnitude was about 7.5. Were the earthquake’s epicenter was located is unknown. Its location is believed to have been somewhere around New Madrid, Missouri, along a fault that runs perpendicularly to the Reelfoot Fault.

No noticeable damage to area was reported; however, landscape changes, like the ones that occurred on December 16, are believed to have happened place. The third quake happened on February 7th in 1811.The shocks epicenter was located near New Madrid, Missouri as well. It hit at 3:45 in the morning and resulted in the destruction of the region known as New Madrid. Structural damage occurred in St. Louis, Missouri as well. Several chimneys fell because of the ground vibration. The landscape was damaged in several ways including; the warping of the ground through sinking and uplift, sand blows, ground cracking, landslides, and stream bank calving. Also Lake St. Francis in Arkansas, a body of water formed because of subsidence that came from earlier earthquakes that happened in the New Madrid seismic zone. Flatboat operators reported that the flow of the Mississippi River was suddenly reversed; however, studies since that time show that the tremors produced northward-moving water waves that made it look like the river had reversed its course.

So in conclusion, the New Madrid earthquakes were a series of three large earthquakes that happened between December 1811 to February 1812 in New Madrid, Missouri. They were once believed to have been the largest earthquakes ever, this theory has since then been proven otherwise. Although the earthquake did a lot of damage to cities and man made structures, it also created beautiful things like Lake St. Francis in Arkansas and formed the spectacular landscape that we know today.