The first of three earthquakes, ranked among the largest in United States history, struck the US Midwest on 19 Dec 1811. In the aftermath of Japan's earthquake- and tsunami-triggered nuclear disaster, the 200th anniversary promises to focus attention on the US nuclear reactors that sit on or near major earthquake zones. Some reports say 15 similar in design to the stricken Japanese reactors sit along the New Madrid Fault Zone, which gave rise to the 1811 quakes.
; ; The area of strong shaking of the so-called New Madrid earthquakes was two to three times as large as that of the 1964 Alaska earthquake and 10 times as large as that of the 1906 San Francisco earthquake, according to the US Geological Survey (USGS). Shaking strong enough to alarm the general population (intensity greater than or equal to V) occurred over an area of 2.5 million square kilometers. People were awakened by the shaking in New York City, Washington DC and Charleston, South Carolina. ; Latter-day estimates, based on the area of shaking and other factors, put the range of intensity between 8.7 and 9.0 on the Richter scale. The final quake occurred on 7 Feb 1812 in the Mississippi River settlement of New Madrid, Missouri (present day Memphis). By the time of the third quake, shaking had forced sand to erupt at the surface, triggered landslides, and caused ground elevation changes over large areas. Seismographs were not available at the time. ; The USGS notes that large waves were generated on the Mississippi River by seismically-induced ground motions during the quakes, deforming the riverbed. Local uplifts of the ground and water waves moving upstream gave the illusion that the river was flowing upstream. Ponds of water also were agitated noticeably. ; The Japanese nuclear disaster has revived debate over US nuclear safety. Some 20 per cent of US electricity is supplied by nuclear power. The ABC News network and Britain's Daily Mail newspaper are among the many news sources pointing out that there are 15 Fukishima-like reactors along the New Madrid Fault Zone. ; The area around the seismic zone was sparsely settled in 1811. The Federal Emergency Management Agency (FEMA) says the area is still at significant risk, It pointed out on the 199th anniversary that the area has experienced explosive growth in both population and infrastructure, and another series of earthquakes of similar intensity today could prove catastrophic both to the region and the rest of the country. Loss of the bridges over the Mississippi River, the largest river system in North America,could cut the country in half. And as the Midwest is a major food-producing region, radiation contamination could precipitate a food supply crisis. ; ;
Date written/update: 2011-12-19