How a Massive Earthquake Split Tennessee’s Largest Lake from the Mississippi River

Imagine an earthquake so powerful it makes the Mississippi flow backward. Across a period of three months stretching from December 1811 to February 1812, a series of earthquakes in the Southeast corner of Missouri and surrounding areas were so powerful they were felt across a million square miles.

These massive earthquakes:

• Happened in the Mississippi River valley but were felt as far away as Boston, Washington D.C., and New York City.
• Lasted for three months with some estimates of the largest earthquake registering 8.5 on the Richter scale. For comparison, the 1906 earthquake that destroyed San Franciso is estimated at a 7.9.
• Crated sand boils stretching more than a mile, spewed golf ball size tarballs, and even turned the sky pitch black.
• And even shifted the Mississippi River so much the earthquakes created what today is the largest lake in Tennessee – Reelfoot Lake.

What happens when massive earthquakes shifts the land around one of the largest rivers in the world?  The land heaves, trees twist, landslides erupt and the ground opens deep crevices. How could an entire new lake be formed by an earthquake? Let’s find out.

What happened during the New Madrid earthquakes?

The New Madrid earthquakes took place between December 16, 1811 and February 7, 1812. At the time, the western frontiers of the United States were lightly populated, mostly with forts and small settlements. The earthquakes are notable because they occured in an area not known for seismic activity, and to this day remain the largest earthquake east of the Rocky Mountains in recorded history.

Let’s dive into each of the earthquakes that occurred across these three months.

• Earthquake 1: December 16, 1811, northeast Arkansas, 2:15am local time. M7.5. Affected an area of 600,000 square kilometers and although there were not many man-made structures at the time there were chimneys broken and the ground shook violently. The earthquake could be felt as far as New York City! The town of Little Prairie, Missouri was destroyed.
• Aftershock 1: December 16, 1811, 7:15am. Although considered an aftershock it still was an estimated magnitude of 7.0 and was felt by people as far as the East Coast.
• Aftershock 2, 3 and 4: Powerful aftershocks were recorded on December 16 and 17th
• Earthquake 2: January 23, 1812, New Madrid, Missouri, M7.3. Reported as the mildest of the three major earthquakes but still destructive causing landslides and riverbanks to collapse.
• Earthquake 3: February 7, 1812, New Madrid, Missouri, between eastern Missouri and western Tennessee, M7.5 (with some estimates reaching as high as M8.6). New Madrid was hit again and this time it would destroy the entire town. In St. Louis Missouri, many houses suffered damage. The death toll for all of the earthquakes is estimated at around 1,000 people.

Did the Mississippi River really flow backward for several hours?

Yes! The earthquake on February 7, 1812 caused the Mississippi to flow backward for several hours.  The violent movement of the earth created a “fluvial tsunami”, essentially meaning a river tsunami. The land under the river raised up and forced the water to run in the opposite direction before everything settled back down, returning the river to a southern flow.

What is the name of the 15,000 acre lake formed by a massive earthquake?

Reelfoot Lake was formed by the New Madrid Earthquakes of 1811-1812. The 15,000-acre lake is in the far NW corner of Tennessee with the nearest town being Tiptonville. Incredibly, while Reelfoot Lake is only a little more than 200 years old, today it’s Tennessee’s largest natural lake!

How was Reelfoot Lake formed?

During the third major earthquake, on February 7, 1812, the earthquake created huge waves on the Mississippi River destroying boats and sending other boats ashore. The river banks were not able to contain the river and the eastside of the riverbank collapsed sending millions of gallons of water onto dry land. All of this water began to pool in an area where the earth had shifted opening up some areas 5 to nearly 20 feet deep! Although some of the water receded back into the river a 15,000 acre, 20-mile-long lake remains!

How deep is the lake formed by a massive earthquake?

Reelfoot Lake is 5-18 feet deep with the average depth being 5 feet. Many of the areas are only 3 feet deep or characterized as swamp. Today about 30 rare or endangered species live near or in the lake, that includes amphibians, snakes, turtles, and many other species. With few large natural lakes around it, Reelfoot Lake has become somewhat of a haven for many species of wildlife ranging from reptiles, to birds, to insects.

What is at the bottom of Reelfoot Lake?

If you scuba-dived to the bottom of Reelfoot lake (remember it is not that deep) you wouldn’t find an underwater ghost town of a flooded city. The area in 1812 was a Cypress forest with tall majestic trees. Many of the trees died out from the water so the bottom of the lake is studded with Cyrpess tree stumps, but there are still large populations of Cypress trees that continue to grow in and around the lake.

What kind of fish live in Reelfoot Lake and how did they get there?

If a brand new lake is formed by a massive earthquake suddenly, how does wildlife adjust? Certainly, there was wildlife that didn’t make it that were living in the Cypress forest when the water flooded the area. But many water birds and birds of prey were able to remain. The fish that used to live in the Mississippi River before getting displaced to the new Reelfoot Lake, now made the Lake their home. Today you can find bluegills, crappies, largemouth bass, and even catfish in the Lake.

What other animals live around Reelfoot Lake?

This area is known for its bald eagle populations. The Reelfoot National Wildlife Refuge is located in the northern part of the lake and provides a protected area for bald eagles and other migratory waterfowl like wood ducks.

Are there alligators in Reelfoot Lake?

Alligators are not common in Tennessee; they typically prefer the warmer climates of Louisiana, Alabama, Georgia, and Florida. However, due to habitat loss, more alligators are moving north to find new homes including areas of western Tennessee. There have not been sightings of alligators in Reelfoot Lake but the swampy areas along the shore would make for a good alligator habitat.  

Are there poisonous snakes in Reelfoot Lake?

There are four species of poisonous (venomous) snakes in Tennessee. Cottonmouths (or water moccasins) are an aquatic snake that could make the lake their home but there does not seem to be common sightings. The broad-banded watersnake are a subspecies of the southern watersnake and live in Reelfoot Lake but are a non-venomous snake and NOT dangerous. These snakes can grow to be 3 feet long and are a heavy-bodied snake, with a body-color of dark yellow with dark brown banding.

Has there ever been another lake formed by a massive earthquake?

Yes! Big Lake on the Arkansas and Missouri border was also created during the earthquakes of 1811-1812. Today the Big Lake National Wildlife Refuge manages the 8,138-acre lake and surrounding area. The average depth of the lake is only 3 feet and much of the area is swampland. It is a popular migration spot for waterfowl and can have up to 200,000 wood ducks in the winter. River otters and beavers make this area their home as well. If you want to try to beat the largemouth bass record this might be the spot to fish since the Arkansas record-breaking largemouth was caught here weighing 16 lbs 8 oz.

Could an earthquake like the New Madrid Earthquake of 1811-1812 happen again?

Yes! Scientists from Stanford have concluded that massive earthquakes along the New Madrid fault could happen again. The good news is they might not happen again until the year 2311. Their research stated, “Paleoseismic evidence collected in recent decades indicates that strong “earthquake triplets” similar in magnitude to the 1811-12 temblors have occurred approximately every 500 years along the New Madrid fault and are likely to happen again.” Perhaps a few new lakes will be formed in the aftermath of the Great Midwest Earthquakes of 2311.

The photo featured at the top of this post is © anthony heflin/Shutterstock.com