New Madrid Earthquakes (1811-1812): Shaking the Mississippi

The New Madrid earthquakes were a sequence of three very large earthquakes and thousands of aftershocks that struck the central Mississippi Valley between December 1811 and February 1812. Centred near the small river town of New Madrid, in what is now southeastern Missouri, they cracked the ground, sank forests, created new lakes and briefly made the Mississippi River flow backward. They remain the most powerful earthquakes recorded east of the Rocky Mountains and still define the seismic risk of the central United States.

Background: a frontier on a hidden fault

In 1811 the middle Mississippi was a frontier. The United States had acquired the region in the Louisiana Purchase of 1803, and New Madrid was a trading settlement of a few hundred people on the west bank of the river. Farmers, traders, flatboat crews and Native American communities, including Shawnee, Delaware, Chickasaw and Cherokee, lived scattered across the lowlands.

Beneath them lay a structure no one then understood: the Reelfoot Rift, an ancient zone of weakness in the North American plate. Most large earthquakes happen at plate boundaries, but the New Madrid Seismic Zone sits far from any boundary. It is an “intraplate” zone, where old faults inside the continent occasionally slip under stress. Because the crust of the central and eastern United States is old, cold and stiff, seismic waves travel much farther there than in California.

What happened

The first great shock struck at about 2:15 a.m. on 16 December 1811, probably in northeastern Arkansas. People were thrown from their beds, log cabins collapsed and chimneys fell. A second very strong shock followed around dawn the same day, and aftershocks continued almost without pause.

The second main earthquake came on 23 January 1812, centred somewhere in the Missouri Bootheel or western Kentucky. The third, on 7 February 1812, was probably the strongest of all. It struck on the Reelfoot fault close to New Madrid and destroyed what was left of the town.

Eyewitnesses described land rolling in waves, trees snapping, and the ground splitting open. Sand and water burst out of the earth in “sand blows”, a sign of liquefaction, in which shaking turns waterlogged soil into a quicksand-like slurry. Large areas of forest sank and flooded, while other areas rose. Riverbanks collapsed into the Mississippi, sweeping away trees and boats.

One of the best-known accounts came from Eliza Bryan, a resident of New Madrid, whose letter describing the terror, the sulphurous smell and the boiling river was published a few years later. Other reports came from boatmen and travellers caught on the river.

The river that ran backward

The most famous effect occurred during the February shock. Movement on the Reelfoot fault pushed up a section of the riverbed near the Kentucky Bend, a loop of the Mississippi. Boatmen reported that this created temporary waterfalls and caused the current to flow upstream for several hours, carrying boats back against the normal flow.

The earthquake also helped form Reelfoot Lake in northwest Tennessee. Land there sank and was flooded, creating a shallow lake of cypress swamps that today covers roughly 60 square kilometres. Smaller “sunk lands” formed across the region and were mapped by geologists a century later.

Among those on the river was the steamboat New Orleans, built by Nicholas Roosevelt in partnership with Robert Fulton and Robert Livingston, whose Clermont had pioneered commercial steam navigation. On its maiden voyage from Pittsburgh to New Orleans, it passed through the stricken region in December 1811, finding a changed river full of fallen trees and shifting channels.

How far it was felt

The shaking was felt across much of the eastern half of the continent. Reports came from places as far away as Detroit, Pittsburgh, Charleston and Washington, D.C., where people noticed swaying buildings and rattling windows. The area of noticeable shaking was many times larger than that of the 1906 San Francisco earthquake, because of the efficient way seismic waves travel through the old crust of eastern North America.

Damage near the epicentres was severe, but the population was so small that loss of life was limited. Historians do not know how many people died. A few deaths were recorded, and others, especially among boat crews and Native American communities, probably went unreported.

Consequences and relief

Many settlers abandoned the New Madrid area, and land values collapsed. In 1815 Congress passed an act allowing owners of land damaged by the earthquakes to exchange it for public land elsewhere in Missouri Territory. This is often described as the first federal disaster relief measure in United States history.

The scheme was quickly abused. Speculators bought “New Madrid certificates” cheaply from original owners and used them to claim valuable land elsewhere, sometimes far from any earthquake damage. Disputes over these claims dragged on in courts for years.

Scientifically, the earthquakes went largely unexplained for over a century. In 1912 the geologist Myron Fuller of the US Geological Survey published the first major scientific study, mapping fissures, sand blows and sunk lands that were still visible.

Myths and facts

A popular legend claims that the Shawnee leader Tecumseh predicted the earthquake as a sign to unite Native nations against the United States. Tecumseh was indeed travelling among southern nations in late 1811, and the earthquake was widely seen as an omen, especially after the Battle of Tippecanoe that November. But stories of a precise prophecy appear only in later sources and cannot be verified.

Another popular story holds that the shaking rang church bells in Boston. Contemporary evidence for this is weak, and it may be an exaggeration of genuine reports of bells ringing in towns closer to the Mississippi Valley.

A more recent myth involves prediction. In 1990 a self-described climatologist, Iben Browning, forecast a major New Madrid earthquake for early December of that year. Scientists rejected the claim, but it caused school closures and widespread anxiety. No earthquake occurred.

Timeline

• 1803: The Louisiana Purchase brings the New Madrid area under United States control.
• 1811, 16 December: The first main earthquake strikes at about 2:15 a.m., followed by a large aftershock at dawn.
• 1811, December: The steamboat New Orleans passes through the shaken region on its maiden voyage.
• 1812, 23 January: The second main earthquake strikes.
• 1812, 7 February: The third and probably strongest shock destroys New Madrid; the Mississippi briefly runs backward.
• 1815, 17 February: Congress passes the New Madrid relief act for owners of damaged land.
• 1912: Myron Fuller publishes the first detailed scientific study of the earthquakes.
• 1990, December: A widely publicised but unscientific prediction of a new New Madrid earthquake fails.

Legacy and modern risk

Geologists now know that the New Madrid Seismic Zone has produced large earthquakes repeatedly over thousands of years, recorded in buried sand blows. Smaller earthquakes occur there frequently. The US Geological Survey estimates a chance of roughly 7 to 10 percent of a magnitude 7 or greater earthquake in the zone within 50 years, and a considerably higher chance of a magnitude 6.

Unlike in 1811, the region now includes cities such as Memphis and St. Louis, along with bridges, pipelines and much of the country’s river traffic. Many older buildings were not designed for earthquakes. The 1811 to 1812 sequence, like the later Charleston earthquake of 1886, shows that dangerous earthquakes are not limited to the western United States.

Why it matters

The New Madrid earthquakes revealed that the stable interior of North America can produce some of the continent’s strongest shaking. They reshaped the landscape of the Mississippi Valley, prompted the first federal disaster relief in the United States, and continue to guide building codes and emergency planning for millions of people today.