Mississippi River Ran Backward During New Madrid Quakes — Popular Mechanics
popular mechanics looks back at the New Madrid earthquakes, when the Mississippi River reportedly ran backward in parts during the last shock. The sequence ran from 1811 to 1812 and left a strange record that still reads like a field note from another planet.
Eliza Bryan, a longtime resident of New Madrid, Missouri, wrote that on December 16, 1811, she was visited by a violent shock of an earthquake, accompanied by a very awful noise resembling loud but distant thunder, but more hoarse and vibrating. She also wrote that the current of the Mississippi was retrograde for a few minutes.
Eliza Bryan in New Madrid
Bryan’s account is the clearest first-person description in the facts here. Her letter to Methodist evangelist Lorenzo Dow describes not just the shaking, but the river itself turning back for a few minutes, which is the detail that makes this quake sequence unusual even by earthquake standards.
Boatmen on the Mississippi River reported the same reversal during the last earthquake. Reports say tectonic uplifts effectively dammed the river in spots and temporarily reversed its flow. The river then took days to wind around the newly formed obstructions.
December 1811 to February 1812
The main shocks came on December 16, 1811, January 23, 1812, and February 7, 1812. Seismologist Otto Nuttli calculated in 1973 that they would have measured approximately 7.2, 7.1, and 7.4 on the body-wave magnitude scale. In 1983, he estimated surface-wave magnitudes as high as 8.5, 8.4, and 8.8 for the three main shocks.
Those numbers help explain why the effects traveled so far. St. Louis sat 150 miles north and had a population of some 5,700 people at the time. Even so, chimneys toppled there, bells rang in Boston, and Dolly Madison was awakened in Washington, D.C., some 900 miles away.
Riverbanks, islands, and damage
The quakes also caused extensive landslides along 125 miles of bluffs on the east side of the Mississippi, and tree-lined river banks collapsed into the river. The small town of New Madrid was severely damaged, and many people switched to living in tents while the quakes continued to rumble in the region.
The river reversal was only one part of a larger physical reset. The earthquakes consumed entire islands and formed new lakes as water rushed into new depressions.
For readers trying to grasp the scale, the unanswered question is not whether the river turned back, but how often a single quake sequence can bend a major river system this far before the flow settles again.
