University of Arkansas System
Type of paper: Thesis/Dissertation Chapter
The New Madrid Seismic Zone
An earthquake is a natural phenomenon resulting from an abrupt release of energy that is stored in the Earth’s crust. This sudden release of energy creates seismic waves. At the surface of the Earth, earthquakes may show up by way of shaking or the displacement of the ground. Sometimes tsunamis are caused in this way. Both earthquakes and tsunamis may result in loss of life as well as property destruction (“Earthquake”).
Earthquakes are caused by friction between tectonic plates. As these plates get stuck, they put a strain on the Earth’s surface. This strain could turn out to be so significant that rocks may give way and fault lines may be created. Earthquakes may also be caused by human activities on the surface of the Earth. Such activities may include the extraction of minerals as well as fossil fuel from the crust of the Earth; the removal of or the injection of fluids into the Earth’s crust; huge explosions; and the collapse of massive buildings (“Earthquake”).
Humans have not yet been able to accurately predict when or where earthquakes would occur. All that they are equipped to do at this time is to estimate the effects of potential earthquakes (“Estimating Earthquake Losses” 50). Even so, the potential loss of human life due to earthquakes cannot be predicted.
In the history of continental United States, the largest known earthquakes have happened in the Mississippi Valley. Estimated over magnitude 8, these earthquakes occurred in the years 1811 and 1812. The New Madrid Seismic Zone was held responsible for the earthquakes. This Zone centers on the New Madrid fault system, and extends from northeastern Arkansas through southeast Missouri and extreme western Tennessee as well as Kentucky to the southern tip of the state of Illinois.
The geological features of the Midwestern United States allow the transmission of seismic waves over a large region. Hence, a major New Madrid earthquake may cause damage to regions away from the New Madrid zone to boot. This larger area covered by an earthquake is what the New Madrid Seismic Zone is made up of. The Zone includes a huge part of eastern Arkansas and Missouri, northwestern Mississippi, western Tennessee as well as Kentucky, in addition to southern Illinois and Indiana (Farley 1-2).
The 1812 New Madrid earthquake was so intense that it caused the Mississippi to begin flowing backward. The earthquake laid waste to whole cities, from Chicago to New Orleans, and within minutes obliterated innumerable lives. Flood, fire, and chaos followed the earthquake, making the destruction caused by the seismic waves even more serious (Williams).
The American heartland has drastically changed ever since the largest earthquake in the continental United States occurred. Missouri is, of course, more populated than it was at the time of the largest earthquake. Human activities that may bring about an earthquake have also increased. Besides, the Mississippi is nowadays penned within a modern system of reservoirs, flood walls, in addition to levees. Few of these modern systems are earthquake proof, however (Williams). Hence, the damage expected to occur with a new earthquake is unimaginable.
From geological records, scientists have gathered that huge earthquakes have rocked New Madrid in 500 AD, 900 AD, 1530 AD, and 1811-12 AD. A large earthquake was predicted within a few hundreds years as recently as May 1999. Some seismologists disagreed with the prediction, and noted that whereas the San Andreas Fault was shifting up to two inches every year, New Madrid hardly moved – less than 1/10th of an inch every year. At this rate, seismologists predicted, it could take around ten thousand years for another major earthquake to occur.
This prediction was challenged by additional seismologists, who pointed out that since the New Madrid fault is buried quite deep – under three thousand feet of sediment in some places – the movement of the ground may not be telling on the surface. Moreover, the New Madrid is located in the center of a tectonic plate. Hence, comparisons with the San Andreas Fault are virtually meaningless (Simon). In other words, a major earthquake could strike Missouri and the other areas covered by New Madrid, at any time.
A news report published in November 1999 stated that the Mississippi River Valley cities including St. Louis and Memphis were in grave danger of being rocked by a severe earthquake. Geologists had found faults similar to the ones responsible for the Northridge quake that damaged Los Angeles in 1994, all along the fault region of New Madrid, extending through Arkansas, Missouri, Kentucky, Illinois, and Tennessee.
In the event of an earthquake, geologists warned, the entire land covered by the New Madrid zone would turn into jelly in a process referred to as liquefaction. This would cause buildings to collapse, and the people would be caught unawares. Geologists do not know when a large earthquake would occur again along the New Madrid fault line. Still, they estimate that it could happen within 500 years of the 1812 earthquake (“Report: Mississippi Valley at Risk of Big Quake”).
Along the New Madrid fault line, a 4.2 magnitude earthquake hit northeast Ohio on 26 January 2001. Another moderate earthquake was reported in southern Indiana on 18 June 2001. Although new injuries were reported, this earthquake is known to have broken glass, thrown objects off of shelves, and also cracked chimneys. In September 2004, yet another earthquake was reported in central Indiana and eastern Kentucky. The 3.6-3.7 magnitude earthquake shook buildings but caused no injuries or large scale damage (Hirsch).
In the year 2005, a 3.9 magnitude earthquake was felt in southern Illinois, in addition to western Kentucky, southeast Missouri, northwest Tennessee, as well as eastern Arkansas. This earthquake was a follow up to a 2.7 magnitude quake that happened hours before it (“Illinois, Other States Feel 3.9 Earthquake”).
Gary Patterson reported in the year 2006 that the residents of the area covered by the New Madrid Zone are unprepared for a large earthquake. In point of fact, an earthquake as severe as the one that happened in 1812 could happen at any time. Even a 6.5 magnitude earthquake would cause enormous damage to Missouri and other areas in the New Madrid Zone. “It won’t take a catastrophic earthquake to do catastrophic damage,” said Patterson.
What is more, liquefaction would be the main cause of damage due to a large earthquake in the area. Approximately eleven million people are currently living in the New Madrid Seismic Zone. During the initial seventy two hours of a big earthquake of any magnitude, these people would first have to be rescued from collapsed buildings. Finally, countless lives are expected to be lost due to such an earthquake, which could happen announced at any time whatsoever.
1. “Earthquake.” Wikipedia, 2007. Retrieved from http://en.wikipedia.org/wiki/Earthquake. (22 March 2007).
2. “Estimating Earthquake Losses.” The Futurist, Vol. 23, Issue 4, July-August 1989.
3. Farley, John E. Earthquake Fears, Predictions and Preparations in Mid-America. Carbondale, IL: Southern Illinois University Press, 1998.
4. Hirsch, Stuart A. “Mild Earthquake Rattles Central Indiana.” New Madrid Fault Beware, September 13, 2004. Retrieved from http://www.greatdreams.com/madrid.htm. (22 March 2007).
5. “Illinois, Other States Feel 3.9 Earthquake.” New Madrid Fault Beware, June 21, 2005. Retrieved from http://www.greatdreams.com/madrid.htm. (22 March 2007).
6. Patterson, Gary. “Expert Warns of Earthquake Zone in New Madrid Zone.” New Madrid Fault Beware, June 18, 2006. Retrieved from http://www.greatdreams.com/madrid.htm. (22 March 2007).
7. “Report: Mississippi Valley at Risk of Big Quake.” New Madrid Fault Beware, November 4, 1999. Retrieved from http://www.greatdreams.com/madrid.htm. (22 March 2007).
8. Simon, Stephanie. “Midwest debate over earthquakes growing in magnitude.” Los Angeles Times, May 1999.
9. Williams, Walter J. The Rift. Toronto, Canada: HarperPrism, 1999.