Early reports indicate that there was only minimal damage to buildings no known deaths in the sparsely populated area of southeastern corner of the state. The shaking was felt widely throughout the region. New Madrid resident Eliza Byran told The Southeast Missourian newspaper that the quake woke her up. She said it sounded like "loud but distant thunder, but more hoarse and vibrating, which was followed in a few minutes by the complete saturation of the atmosphere, with sulphurious vapor, causing total darkness."That's how the story might have been reported on the day that the New Madrid fault line buckled in late 1811. This Friday, December 16, 2011, is the 200-year anniversary of the what has come to be known as "the New Madrid Earthquake." There were actually three powerful quakes, however. If - or when - the New Madrid fault line trips again the news would be much more grim because there is so much more development today. The town of New Madrid, MO was incorported in 1808, only three years before the earth shook beneath it.
The U.S. Geological Survey (USGS) estimates that the first New Madrid quake on December 16, 1811 was a magnitude 7.7. That's huge, the biggest recorded in U.S. history.The earthquake was felt widely over the entire eastern United States, says the USGS. "People were awakened by the shaking in New York City, Washington, D.C., and Charleston, South Carolina.
Perceptible ground shaking was in the range of one to three minutes depending upo the observers' location. The ground motions were described as most alarming and frightening in places like Nashville, Tennesse, and Louisville, Kentucky. Reports also describe houses and other structures being severely shaken with many chimneys knocked down. In the epicentral area, the ground surface was described as in great convulsion with sand and water ejected tens of feet into the air (liquefaction)."
The Southeast Missourian reports that there will be bicentennial anniversaries in 2012 on Jan. 23 and Feb. 7 for the subsequent two New Madrid quakes, which the USGS estimates measured at 7.5 and 7.7.
Accounts of the earthquakes from that time include newspaper articles that said the earthquakes were felt halfway across the country in Washington, D.C., and Boston, where the shaking caused church bells to ring. The USGS sums up the immense power of the powerful New Madrid quakes (my emphasis added):
The first principal earthquake, M7.7, occurred at about 2:15 am (local time) in northeast Arkansas on December 16, 1811. The second principal shock, M7.5, occurred in Missouri on January 23, 1812, and the third, M7.7, on February 7, 1812, along the Reelfoot fault in Missouri and Tennessee.
The earthquake ground shaking was not limited to these principal main shocks, as there is evidence for a fairly robust aftershock sequence. The first and largest aftershock occurred on December 16, 1811 at about 7:15 am. At least three other large aftershocks are inferred from historical accounts on December 16 and 17. These three events are believed to range between M6.0 and 6.5 in size and to be located in Arkansas and Missouri.
This would make a total of seven earthquakes of magnitude M6.0-7.7 occurring in the period December 16, 1811 through February 7, 1812. In total, Otto Nuttli reported more than 200 moderate to large aftershocks in the New Madrid region between December 16, 1811, and March 15, 1812: ten of these were greater than about 6.0; about one hundred were between M5.0 and 5.9, and eighty-nine were in the magnitude 4 range. Nuttli also noted that about eighteen hundred earthquakes of about M3.0 to 4.0 during the same period. More at the USGS site.
