Earthquakes & the New Madrid zone

The southeast corner of Missouri — the Bootheel — sits on the New Madrid Seismic Zone, a buried system of faults that runs across several states. It's the most dangerous earthquake zone east of the Rocky Mountains. Unlike a storm, an earthquake gives no warning at all.

Earthquakes strike with no warning — no watch, no warning, no siren. That's why the safety is all in what you do automatically during the shaking, and what you prepare ahead of time.

A first-hand warning from history

1811–1812: when the river seemed to run backward

In the winter of 1811–1812, a series of enormous quakes (estimated around magnitude 7 to 8, from December 16, 1811 to February 7, 1812) centered in the Bootheel. They were felt across much of the eastern United States — accounts tell of church bells ringing hundreds of miles away, famously as far as Boston. The ground liquefied into 'sand blows' and buckled; for a short time the Mississippi River even appeared to flow backward — an illusion created by huge waves (called seiches) and the riverbed lifting — and across the line in Tennessee, the land sank and Reelfoot Lake formed.

Quiet, but not asleep

Still active

The zone is still active. Instruments record around 200 small (magnitude 1+) quakes a year — most too small to feel — with felt events most years, a magnitude 4 or larger roughly every 18 months, and a magnitude 5 or larger about once a decade.

Scientists at the USGS estimate roughly a 25 to 40 percent chance of a magnitude 6 or larger, and about a 7 to 10 percent chance of a repeat of the 1811–1812 scale, in the next 50 years. These are long-range probability estimates — not a prediction, and not a countdown. They're a reason to prepare, not to panic.

Why the ground matters

Why a big one would hit hard here

Two things make a big New Madrid quake especially serious here: a lot of older, unreinforced-masonry buildings (brick that isn't tied together to flex), and the solid bedrock of the central U.S., which carries shaking over a much larger area than the same-size quake would on the West Coast.

Done before the shaking

Prepare ahead (most of earthquake safety)

Most of earthquake safety is done before the ground ever moves: anchor tall furniture, bookcases, and the water heater to the wall; move heavy and breakable things to low shelves; and know where your utility shutoffs are.

Because a major quake could damage roads, water, and power across a wide area, plan to be self-sufficient for days to weeks — longer in the southeast than most Missourians would need for a storm.