The greatest earthquake ever recorded occurred in New Madrid, Missouri, in 1812.

From December 16, 1811, to February 7, 1812, about 2,000 minor earthquakes took place in Missouri, Arkansas, Illinois, and Tennessee.

A Tree Uprooted by the Earthquake.  Photo Credit: The Virtual Times.

The largest of all was the New Madrid earthquake.  It is believed to have had a force of 8.8 on the Richter scale, greater than any other earthquake every measured.

The results of the earthquake were amazing.  Over 150,000 acres (60,000 ha) of forest were flattened, and fissures miles long cut up the earth.  The town of New Madrid sank 12 feet into the ground, and many neighboring villages were completely flattened.  Even the Mississippi River began to temporarily flow North rather than South.

Extensive soil liquefaction also resulted from the earthquake.  Soil became mud and covered the ground for miles.

The effects of the quake were felt for great distances.  Sleeping people woke up in Ohio, and even far-off Washington DC shook from the earthquake. 

The damage in terms of human life was limited.  Back then, few people lived in the area and the US population was much smaller.

Earthquakes such as the one in New Madrid remain a major threat to human civilization.  It remains extremely difficult to know when and where earthquakes are coming, and societies are unprepared to handle the effects of a giant quake.  Even if one tried, it would be almost impossible to create a city that could stand up to an earthquake like the one at New Madrid.

A resource on the earthquake

Many links and the history of the earthquake