New Madrid Seismic Zone: Earthquake Risk, History & Live Activity
The New Madrid Seismic Zone is a set of buried faults in the central United States, beneath the Mississippi River valley where Missouri, Tennessee, Arkansas, and Kentucky meet. It lies far from any plate boundary, an intraplate zone reactivating ancient faults deep within the North American plate, yet it produced the largest earthquakes in the recorded history of the eastern United States. It remains active today, generating around 200 small earthquakes a year.
How likely is a large earthquake?
The U.S. Geological Survey estimates a 25 to 40 percent chance of a magnitude 6 or larger earthquake in the New Madrid zone over the next 50 years, and roughly a 7 to 10 percent chance of a repeat of the great 1811 to 1812 sequence, about magnitude 7 to 8, in the same period. Current modelling implies a recurrence interval of roughly 500 to 1,200 years for the largest events.
Because the central United States sits on hard, old crust, shaking there travels much farther than it does in California, so a given magnitude is felt across a far wider area. Much of the region's building stock was never designed for earthquakes, which is why a moderate New Madrid event can carry outsized consequences. The steady small earthquakes neither raise nor lower the odds of a large one; they simply confirm the zone is active.
Live seismic activity near this fault
Counts include M2.5+ events — the smallest size USGS reports consistently worldwide.
No magnitude 2.5+ earthquakes recorded near this fault in the last 7 days.
History
The zone's defining events are the three great earthquakes of the winter of 1811 to 1812, among the most powerful known in eastern North America.
- 16 December 1811 (estimated M7.5) — the first mainshock, near northeastern Arkansas.
- 23 January 1812 (estimated M7.3) — the second mainshock.
- 7 February 1812 (estimated M7.5) — the third, near New Madrid, Missouri, which locally reshaped the Mississippi River channel.
- 1895 Charleston, Missouri (M6.6) — the largest well-documented event in the zone since 1812.
Frequently asked questions
Is the New Madrid zone overdue?
Not in the sense the word implies. The best estimates put the interval between great New Madrid earthquakes at several hundred to over a thousand years, and about 210 years have passed since 1811 to 1812, well short of that average. The USGS frames the hazard as a modest but real probability over the coming decades, not as an imminent event.
Would a New Madrid earthquake affect a wide area?
Yes. Because of the region's rigid, ancient crust, energy from a New Madrid earthquake spreads far more efficiently than in the West. The 1811 to 1812 shocks were felt across much of the eastern United States and rang bells hundreds of kilometres away. A large modern event could bring damaging shaking to Memphis, St. Louis, and many smaller communities across several states.
Nearby regions
Live counts from the USGS earthquake feeds within 300 km of the fault. Magnitudes and depths are automated readings and may be revised. Not for emergency use.