In the United States, most people may erroneously believe that earthquakes are a strictly West Coast phenomenon. Did you know a quake that might devastate St. Louis and severely rattle the Greater Kansas City area is a real possibility?
The New Madrid fault line extends 120 miles in southeastern Missouri (the "boot heel") and into northeastern Arkansas. According to Missouri State Emergency Management Agency, it's an extremely active seismic zone.
While damaging tremors may be more frequent in California, when they occur along the New Madrid line, the impact can be far more widespread. Due to the underlying geology in the area, a New Madrid earthquake may cause destruction in an area about 20 times larger than an earthquake with a southern California epicenter.
'Major' Quake Every 200 to 300 Years
A "major" earthquake, classified as registering 7.5 or higher on the Richter scale, strikes the New Madrid seismic zone about every 200 to 300 years. The last major earthquakes to rock the region occurred in 1811 and 1812. During a 5-month stretch, more than 2,000 tremors were noted - 5 of which were estimated to top 8.0 on the Richter scale - and 18 shock waves reached the Eastern seaboard, some with enough force to cause church bells to ring.
Perhaps the most famous anecdote associated with the 1811 and 1812 earthquakes is that some of them caused the Mississippi River to flow backward. Fortunately, in the early 19th Century modern-day Missouri was considered "out west," and this region of America was sparsely populated.
Today, a rupture of the New Madrid fault on the magnitude of the 1811-12 earthquakes could leave large parts of St. Louis and Memphis, Tennessee, uninhabitable. According to a 2010 study that the University of Illinois conducted and the Federal Emergency Management Agency commissioned, a 7.7-magnitude earthquake in this area could leave more than 7 million people homeless.
These are excerpts from a journal George Heinrich Crist kept as he and his family endured the 1811-12 New Madrid earthquakes. They lived near present-day Louisville, Kentucky, more than 250 miles away from epicenter in New Madrid, Missouri. (Excerpts are republished as written by Crist.)
December 16, 1811
"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 cold hear was screams from people and animals. It was the worst thing that I have ever wittnesed. It was still dark and you could not see nothng. I thought the shaking and the loud roaring sound would never stop. You could not hold onto nothing neither man or woman was strong enough - the shaking would knock you lose like knocking hicror nuts out of a tree. I don't know how we lived through it. None of us was killed - we was all banged up and some of us knocked out for awile and blood was every where. 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 will have to hunt our animals. Every body is scared to death. we still do not know if anybody was killed."
January 23, 1812
"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 lays 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 Amandy Jane in this one - a log fell on her. We will bury her upon the hill under a clump of trees where Besys Ma and Pa is buried. A lot of people thinks that the devil has come here. Some thinks that this is the beginning of the world coming to a end."
February 8, 1812
"If we do not get away from here the ground is going to eat us alive. We had another one of them earth quakes yesterdy and today the ground still shakes at times. We are all about to go crazy - from pain and fright. We can not do anything until we can find our animals or get some more. We have not found enough to pull he wagons."
The cost of property damage would quickly soar to billions of dollars. Flooding along the Missouri and Mississippi Rivers would be likely, and parts of the central United States might be without power for weeks.
The FEMA study urges state and local governments to retrofit hospitals, fire stations, police stations, nuclear power plants and other essential facilities to improve their odds of holding up in a big earthquake.
The St. Charles County (Missouri) Division of Emergency Management puts the odds of another major New Madrid earthquake happening before 2040 at 25 percent.
Depiction of a sunken steamboat in the Mississippi River after 1812 quake
- On average, scientists record about 20 "events" in the New Madrid seismic zone registering more than 1.0 on the Richter scale each month.
- A tremor strong enough to be felt (2.5 to 3.0 on the Richter scale) usually happens at least once a year.
- A magnitude 5.0 or higher shock strikes about once per decade and generally causes damage in a multitude of states.
- A "damaging" earthquake (6.0 or greater) occurs in this area about every 80 years, according to seismologists. The last one to hit the area was in 1895.
- The 1811 and 1812 earthquakes that shook the New Madrid zone were several times more powerful than the infamous 1906 earthquake that left much of San Francisco in ruins.
This photo from the mid-19th Century shows a tree that survived the 1811 and 1812 New Madrid earthquakes. However, because quake caused the ground to sink several feet the tree's roots were exposed.