Special Links

 

 

    

    

    

    

 

Hit Counter

 

NEW MADRID FAULT       

Much has been written and discussed about the New Madrid Fault but little has been done for preparedness for another catastrophic event like the quake of 1811-12 yet tremors continue and a quake of a larger magnitude is a probability.


Earthquake
Safety  

http://www.cusec.org/

  Earthquake Mitigation  
  Family Safety
  Home Survival Pack
  Personal Disaster Kit


Shake, Rattle, 'n Roll:

The New Madrid Fault Past and Present

Jennifer Dondlinger

Honors Colloquium: "Dirt in the Disk Drive"

When you think of California, your mind probably conjures up images of warm sunny beaches, oranges, palm trees, the Pacific Ocean, sun tan lotion, blondes in bikinis, muscle men, surfers, the Beach Boys, night clubs, Hollywood, the rich and the famous, and, of course, earthquakes. The San Andreas fault is the source of California's major eruptions (Lowell, 1996). One of the most infamous earthquakes to rock California hit on April 18, 1906 with the strongest tremor measuring 8.3 on the Richter scale (Cherny, 1996). This quake was responsible for a fire that burned uncontrollably in San Francisco for three days and two nights. Various other major earthquakes dot California's shaky history and are expected to continue into the future (Lowell, 1996). As a result, California has developed and implemented earthquake safety measures to prevent loss of life and property (U.S. Geological Survey Circular, 1990). Although California's beauty is alluring, its earthquakes are less than inviting.

An earthquake is a vibration of the Earth's surface due to elastic waves (Sharnberger, 1996). Earthquakes are divided into two types based on the depth of their focus (Zobach, 1996). These types are a shallow to moderate focus or a deep focus earthquake. The focus is the origin of the quake's vibration. A shallow to moderate focus is less than 70 kilometers below the Earth's surface in a layer called the lithosphere. The most destructive and common types of quakes occur at this depth. Earthquakes occurring at 70 to 700 kilometers are deep focus events; they are not as common.

ThePlate Tectonics theory explains the causes of an earthquake (Scharnberger, 1996). The main concepts are the lithosphere is composed of moving plates and a resistance towards movement causes stress to build at the plates' boundaries. When a certain level of stress builds between the boundaries, it must be released. One way in which the stress is released is by the tectonic plates in the lithosphere slipping past one another resulting in an earthquake.

Throughout the years, the effects of an earthquake have served as the main determination of its magnitude (Scharnberger, 1996). One of the most well known scales for determining an earthquake's magnitude is the Richter scale developed by professor Charles Richter in the 1930's. The seismograph records the amplitude of seismic waves or magnitude. For example, a one millimeter maximum amplitude recorded 100 kilometers from the epicenter, the region on the surface of the Earth directly above the origin of the quake, is a 3 on the Richter scale. Each ten fold increase or decrease in amplitude is a one step movement on the scale. The Richter scale does not have a maximum value; however, it is not effective in accurately measuring quakes with a magnitude greater than 8.5 as is characteristic of other scales. Each value of the Richter scale signifies a thirty fold increase in the energy released by the earthquake. Scientists are able to make measurements at varying distances from the epicenter because the amplitudes vary consistently with a consistent change in distance.

The severity of the effects of an earthquake depends on three factors: magnitude, distance from the fault, and depth of the foci (Zobach, 1996). The larger the magnitude, the more energy the quake releases and the longer it lasts. Regions closer to the epicenter are more vulnerable to greater destruction. A deeper focus affects a small area.

An earthquake may have various effects on a region. Earthquakes are known to produce fissures, cracks in the land that can range from centimeters to meters in width (Milne, 1939). Land slides as well as changes in the level of water in lakes may also occur. Rivers have been known to overflow, dry up completely, or even change directions as the result of an earthquake. These effects are why California takes earthquake preparation seriously.

Scientists analyze specific warning signs in order to make earthquake predictions. These signs include the angling of land surfaces, varying magnetic and electrical field strengths, and alterations in the direction and amount of water flow (Scharnberger, 1996). A higher frequency of tremors as well as minor eruptions and abnormal animal behavior are also symptoms of an impending quake.

Almost a century before the infamous earthquake that destroyed most of San Francisco, another destructive quake left its horrendous mark not on California but on the central United States. Picture yourself in the early 1800's. You are snuggled warmly in your bed as the mantel clock chimes two o'clock on a December morning. You pull the covers more tightly around you to keep out the cold. The fire burned out hours ago. Dreams begin to fill your head. The mind conjures up images of standing on a stool reaching for a pot on the top self. The stool begins to shake violently and you feel yourself hitting the floor. Suddenly the bed begins to shake as though a continuation of the dream - except it's reality. Your feet struggle to plant themselves firmly on the cold, ground floor as your heart fills with panic and distress. You ask yourself if the world is ending and begin praying to God as the rumbling finally ceases.

This is what roused the people of New Madrid, Missouri and countless other settlements from their beds in 1811 (Penick, 1976). By today's standards, the quake ranged from 8.4 to 8.8 on the Richter Scale, slightly stronger than the San Francisco earthquake of 1906 (Harper, 1996). New Madrid was the closest settlement to the origin of the eruption and from which the fault earned its namesake (Introduction to New Madrid, 1998). This event, widely unknown, started on December 16 and left a path of destruction and terror for months to follow (Penick, 1976).

"As much as I love my place in Kentucky- I never want to go back. From December to April no man- no woman or animal if they could talk would dare to believe what we lived through." George Heinrich Crist; April 14, 1813

The New Madrid fault, the source of the 1811-1812 earthquakes, affects a forty mile wide, two hundred mile long stretch from the Missouri- Illinois border to Memphis, Tennessee (Harper, 1996). Most Americans are not even aware of its existence much less its devastating history.

"There was a great shaking of the earth this morning. tables and chairs turned over and knocked around- all of us knocked out of bed. The roar I thught would leave us deaf if we lived. It was not a storm. When you could hear, all you could hear was screams from people and animals. It was the worst thing that I have ever witnessed. It was still dark and you could not see nothing neither man or woman was strong enough- sound would never stop." George Heinrich Crist, December 16, 1811

During the quake the town of New Madrid dropped more than ten feet in elevation and was flooded by the Mississippi River (Harper, 1996). The Mississippi actually flowed from the south to the north for several hours. The floor of the river buckled causing flooding and the formation of Reelfoot Lake in Kentucky. In fear, many people moved out of their homes into tents and later light wooden structures (Penick, 1976).

 This picture shows a tree's exposed roots as a result of the Mississippi River overflowing during the 1811-1812 New Madrid eruptions (National Earthquake Information Center, 1999).

"When it got day break you could see the damage done all around. We still had our home it was some damage. Some people that the home was not built to strong did not. We still have to hunt our animals. Every body is scared to death. We still do not know if anybody was killed." George Heinrich Crist, December 16, 1811

The wrath of the New Madrid did not cease there. Aftershocks continued along the New Madrid fault until another major eruption, equal in size to the first, occurred a little more than a month later (Penick, 1976).

"What are we gonna do? You cannot fight it cause you do not know how. It is not something that you can see. In a storm you can see the sky and it shows dark clouds and you know that you might get strong winds but this you can not see anything but a house that just lies in a pile on the ground- not scattered around and trees that just falls over with the roots still on it. The earth quake or what ever it is come again today. It was as bad or worse than the one in December. We lost our Amanda Jane in this one- a log fell on her." George Heinrich Crist, January 23, 1812

A third major eruption followed on February 7, 1812 with aftershocks comparable in strength to the main eruption (Penick, 1976). The ground continued to shake for five months afterward. Most of the houses that had remained standing were now destroyed and a mass evacuation resulted.

"If we do not get away from here the ground is going to eat us alive. We had another one of them earth quakes yesterday and today the ground still shakes at times. We are all about to go crazy- from pain and fright." George Heinrich Crist, February 1, 1812

Amazingly the New Madrid earthquakes produced tremors which were felt within one million square miles (Penick, 1976). People as far away as Canada and the Gulf Coast felt the vibrations (Harper, 1996). One thousand eight hundred and seventy-four shocks were recorded for nearly a three month period between December 16 and March 15 (Penick, 1976). Eight of those were considered violent and ten severe.

"You could not hold onto nothing neither man or woman was strong enough- the shaking would knock you lose like knocking hickory nuts out of a tree. I don't know how we lived through it. None of us was killed- we was banged up and some of us knocked out for a while and blood was every where." George Heinrich Crist, December 16, 1811

What would happen if an earthquake similar to the 1811- 1812 eruption occurred today? The U.S. Geological Survey predicts an earthquake of that magnitude would cost billions of dollars in damages and the lives of thousands (1990). People from Denver to New York City would feel the vibrations. Chimneys would collapse in Chicago, Knoxville, Dallas, and Kansas City. The entire Central United States would face structural damages especially to sky scrapers and tall buildings. Are you thinking to yourself, "But we don't get earthquakes in the midwest."? Wrong. The New Madrid fault remains active and another major eruption is possible.

Each cross represents the location of an earthquake eruption since 1974 (Schweig, 1998)

The Geological Survey further predicts that an eruption of 6.0 or larger along the New Madrid will result in large losses (1990). The losses will stem from poorly supported buildings and structures to the amount of people living near the fault. Areas of high population face the greatest danger. The land of the midwest itself is poorly constructed for an earthquake. Far reaching, loose sedimentary rock provide an unstable base that actually promotes ground vibration. A fourth factor is the large area at risk. These factors are aiding the amount of destruction the New Madrid can produce.

(continue)


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Earthquake History of Missouri

Most of Missouri's earthquake activity has been concentrated in the southeast corner of the State, which lies within the New Madrid seismic zone.

The written record of earthquakes in Missouri prior to the nineteenth century is virtually nonexistent; however, there is a geologic evidence that the New Madrid seismic zone has had a long history of activity. The first written account of an earthquake in the region was by a French missionary on a voyage down the Mississippi River. He reported feeling a distinct tremor on Christmas Day 1699 while camped in the area of what is now Memphis, Tennessee.

Whatever the seismic history of the region may have been before the first Europeans arrived, after December 16, 1811, there could be no doubt about the area's potential to generate severe earthquakes. On that date, shortly after 2 AM, the first tremor of the most violent series of earthquakes in the United States history struck southeast Missouri. In the small town of New Madrid, about 290 kilometers south of St. Louis, residents were aroused from their sleep by the rocking of their cabins, the cracking of timbers, the clatter of breaking dishes and tumbling furniture, the rattling of falling chimneys, and the crashing of falling trees. A terrifying roaring noise was created as the earthquake waves swept across the ground. Large fissures suddenly opened and swallowed large quantities of river and marsh water. As the fissures closed again, great volumes of mud and sand were ejected along with the water.

The earthquake generated great waves on the Mississippi River that overwhelmed many boats and washed others high upon the shore. The waves broke off thousands of trees and carried them into the river. High river banks caved in, sand bars gave way, and entire islands disappeared. The violence of the earthquake was manifested by great topographic changes that affected an area of 78,000 to 130,000 square kilometers.

On January 23, 1812, a second major shock, seemingly more violent than the first, occurred. A third great earthquake, perhaps the most severe of the series, struck on February 7, 1812.

The three main shocks probably reached intensity XII, the maximum on the Modified Mercalli scale, although it is difficult to assign intensities, due to the scarcity of settlements at the time. Aftershocks continued to be felt for several years after the initial tremor. Later evidence indicates that the epicenter of the first earthquake (December 16, 1811) was probably in northeast Arkansas. Based on historical accounts, the epicenter of the February 7, 1812, shocks was probably close to the town of New Madrid.

Although the death toll from the 1811-12 series of earthquakes has never been tabulated, the loss of life was very slight. It is likely that if at the time of the earthquakes the New Madrid area had been as heavily populated as at present, thousands of persons would have perished. The main shocks were felt over an area covering at least 5,180,000 square kilometers. Chimneys were knocked down in Cincinnati, Ohio, and bricks were reported to have fallen from chimneys in Georgia and South Carolina. The first shock was felt distinctly in Washington, D.C., 700 miles away, and people there were frightened badly. Other points that reported feeling this earthquake included New Orleans, 804 kilometers away; Detroit, 965 kilometers away; and Boston, 1,769 kilometers away.

The New Madrid seismic zone has experienced numerous earthquakes since the 1811-12 series, and at least 35 shocks of intensity V or greater have been recorded in Missouri since 1811. Numerous earthquakes originating outside of the State's boundaries have also affected Missouri. Five of the strongest earthquakes that have affected Missouri since the 1811-12 series are described below.

On January 4, 1843, a severe earthquake in the New Madrid area cracked chimneys and walls at Memphis, Tennessee. One building reportedly collapsed. The earth sank at some places near New Madrid; there was an unverified report that two hunters were drowned during the formation of a lake. The total felt area included at least 1,036,000 square kilometers.

The October 31, 1895, earthquake near Charleston, Missouri, probably ranks second in intensity to the 1811-12 series. Every building in the commercial area of Charleston was damaged. Cairo, Illinois, and Memphis, Tennessee, also suffered significant damage. Near Charleston, 4 acres of ground sank and a lake was formed. The shock was felt over all or portions of 23 states and at some places in Canada.

A moderate earthquake on April 9, 1917, in the Ste. Genevieve - St. Marys area was reportedly felt over a 518,000 square kilometer area from Kansas to Ohio and Wisconsin to Mississippi. In the epicentral area people ran into the street, windows were broken, and plaster cracked. A second shock of lesser intensity was felt in the southern part of the area.

The small railroad town of Rodney, Missouri, experienced a strong earthquake on August 19, 1934. At nearby Charleston, windows were broken, chimneys were overthrown or damaged, and articles were knocked from shelves. Similar effects were observed at Cairo, Mounds and Mound City, Illinois, and at Wickliff, Kentucky. The area of destructive intensity included more than 596 square kilometers.

The November 9, 1968, earthquake centered in southern Illinois was the strongest in the central United States since 1895. The magnitude 5.5 shock caused moderate damage to chimneys and walls at Hermann, St. Charles, St. Louis, and Sikeston, Missouri. The felt areas include all or portions of 23 states.

Earthquake Information Bulletin, Volume 6, Number 3, May-June 1974, by Carl A. von Hake.

==============================================

Earthquakes in the central or eastern United States effect much larger areas than earthquakes of similar magnitude in the western United States. For example, the San Francisco, California, earthquake of 1906 (magnitude 7.8) was felt 350 miles away in the middle of Nevada, whereas the New Madrid earthquake of December 1811 rang church bells in Boston, Massachusetts, 1,000 miles away. Differences in geology east and west of the Rocky Mountains cause this strong contrast.

http://www.cusec.org/S_zones/NMSZ/nmsz_home.htm

==========================================

(continue Shake, Rattle, Roll)

What exactly is the chance of another major eruption? The statistics about the likelihood of a future damaging earthquake are conflicting. One prediction calls for a 2.7- 4.0% of an 8.0 magnitude or greater, similar to the 1811-1812 quakes, in the next 50 years and a 30% chance for a 7.0 (Patterson, 1998). The probabilities continue to increase with a 6.0 magnitude. There is an incredible 86- 97% chance over the next fifty years resulting in structural damage. The extent of the structural damage could range from cracked foundations to collapsed buildings. An earthquake of 6.5 magnitude could cost $3.6 billion dollars in damage (U.S. Geological Survey Circular, 1990). Another report calls for a 50% chance of a 6.0 or greater by 2000 and a 90% chance by 2040 (Introduction, 1998).

Here in the Midwest, we have been well versed on tornadoes, floods, and fires. We've memorized and practiced drills to handle almost any emergency. We take vaccines against diseases like polio, lock jaw, and measles. We buy life insurance to protect our loved ones in the event of an untimely death. We need to learn what to do in the event of an earthquake. Education is the key. We need to take safety measures to protect our homes and our lives. Mandatory school drills should be implemented for earthquakes just as schools practice for a tornado or fire. People must be aware of earthquake safety just like any other natural disaster.

We need to revise building codes for new construction to make the structures able to withstand earthquakes. Modification is also necessary to existing structures. One of the underlying deficiencies surrounding the New Madrid fault is lack of research and publicity. Much of the nation's attention is focused on the earthquakes that plague California. This attention stems from the higher frequency of eruption's (U.S. Geological Survey Circular, 1990). Though the New Madrid fault erupts less frequently, it affects a much larger area increasing the possible amount of damage. A California earthquake will reach an area only 1/10 as large as a New Madrid quake.

Some advancement has been made to study and prepare for the next major earthquake in the Midwest. The Central United States Earthquake Consortium (CUSEC) was founded in 1983 (Schweig, 1998). The organization promotes public education and earthquake safety research between Midwestern states (Schweig, 1998). Since 1990, the United States Geological Survey (USGS) has increased its focus on the New Madrid seismic zone. Earthquake education has been adopted by many schools including those in Kentucky who mandated it. Three states, Arkansas, Kentucky, and Tennessee, have Earthquake Awareness Weeks. Geologists also completed maps in 1995 depicting which portions of the central U.S. were most susceptible to intense shaking during an eruption. In addition, most states have been working to reinforce existing building structures and develop appropriate earthquake building codes. Kentucky and other states who have shown such insight into earthquake awareness are to be commended, but there is a reluctance among people in other states to take this issue seriously.

While researching the New Madrid fault, I found it extremely difficult to locate predictions for the next eruption. The scientific community is making great strides in their study of earthquakes and earthquake prediction; however, scientists are still not able to provide guarantees. The chance of a tornado striking a tornado prone area is 0.0363 or every 250 years, yet we prepare for them (Tornadoes, 1998). Only one in 2.5 million stand a chance of being struck and killed by lightning every year, although everyone takes shelter at the first sight of it (Weather Flashes- Page 3, 1998). We know how to react to other natural disasters. Now we must learn how to react to earthquakes.

"A massive earthquake hit today. 8.0 on the Richter scale they're saying. Not much damage though a few of the older structures not under the new building codes need repair. It could have been much worse if people hadn't been prepared. The trembling was quite startling, but everyone stayed calm. No casualties have been reported thus far. Mostly people escaped with a few cuts and bruises." Jennifer Dondlinger, April 23, 2009

Hit back button after viewing page to return to New Madrid Fault

http://newmadridonline.tripod.com/earthquakes/index.htm

dancing alphabet  -    link to www.artie.com.