Between mid-December 1811 and mid-March 1812 a series of catastrophic earthquakes shook West Tennessee and the rest of the Central Mississippi Valley. Judging from reports and eyewitness accounts, the quakes would have measured among the highest ever recorded on the modern Richter scale. Some reports said that the quakes were strong enough to awaken sleepers in Washington, D.C., and allegedly some tremors were felt twelve hundred miles away in Quebec City, Canada.
The first of these historic quakes occurred in the St. Francis River area of northeast Arkansas; the second struck five weeks later and several miles to the northeast. Two weeks after that the third and strongest of the three quakes hit the area, with its epicenter still further north, at the little river port town of New Madrid, Missouri. The last of these three quakes is estimated to be the strongest ever recorded on the North American continent.
Geologists associate this early quake activity with the New Madrid or Central United States seismic zone. This ill-defined series of deeply buried faults runs roughly parallel to the Mississippi River Valley. The zone extends from Cairo, Illinois, south through Missouri to Marked Tree, Arkansas. A side branch also extends into the Reelfoot Lake region of northwest Tennessee.
Since the affected region was a sparsely settled frontier, few written accounts exist of the early quakes. According to a few personal diary entries and scanty eyewitness accounts quoted in local newspapers, the endless days and nights of earth tremors and thousands of aftershocks must have been dreadful to experience. Few settlers had ever experienced a quake.
The quakes caused much destruction along the Mississippi River as far south as present-day Memphis and as far up the Ohio River as Indiana. During the strongest of the quakes, great cracks and fissures opened and spewed out sand and water. Gaping crevices formed, some twelve feet wide and deep and more than twenty feet in length. Low waterfalls developed at points along the Mississippi in the vicinity of New Madrid. They were short-lived, however, in the soft sediments of the river valley. Shifting currents and changing flows along the Mississippi, Ohio, Arkansas, and other rivers created and destroyed islands, sandbars, and other familiar features. The quakes caused waves to rush over river banks. Return currents washed countless limbs and even whole trees into the main channels. Massive log jams formed, making navigation even more perilous.
Many boats capsized, and cargoes and crews were never seen again. Seasoned riverboat pilots had to deal with whole new rivers. Cracks and fissures, downed trees, and other obstacles made roads and trails impassable. Massive landslides occurred along the Mississippi and Ohio River bluffs from Memphis to Indiana. Some ground areas rose or fell as much as twenty feet relative to the surrounding landscape. An eighteen- to twenty-acre area near Piney River in Tennessee sank so low that the tops of the trees were at the same level as the surrounding ground. Whole forests sank below their original level and filled with water to form swamps and shallow lakes. The eighteen-thousand-acre Reelfoot Lake was either formed or enlarged during the 1811-12 earthquake episode. In other areas, lakes and swamps rose to higher elevations. Soon their waters drained away or evaporated. In time they evolved into prairies and upland forests. Much of this land now supports Tennessee cotton and soybeans.
As devastating as these early quakes were, destruction in human terms was light. Population was sparse, and Indians, traders, and settlers were quite self-sufficient, capable, and resilient. Due to a lack of census records and other reliable counts, the exact number of people who perished as a result of the quakes will never be known.