Government officials are working with leaders in public safety, emergency response, law enforcement, emergency medical care, faith groups and the Missouri National Guard to strengthen state and local preparedness in the event of an earthquake in the New Madrid Seismic Zone.
Earthquake Program Manager for the State Emergency Management Agency Steve Besemer says the state seizmic safety commission is an advisory body panel of experts that looks at various things affecting earthquake safety — they take that information to the government and to the community.
He says preparing in advance is key to weathering what will be a huge national emergency in the future.
Besemer says there are a number of online resources that provide information on how to be prepared.
He suggests checking out:
The New Madrid Seismic Zone is the nation’s most active seismic zone east of the Rocky Mountains. What are believed to be the three largest earthquakes in history in the continental United States occurred in the area in the winter of 1811 and 1812.
Besemer says a major New Madrid Seismic Zone earthquake could have a significant impact as far away as St. Louis, while also having an impact in Arkansas, Alabama, Illinois, Indiana, Kentucky, Mississippi and Tennessee.
An earthquake commission has been in place for 15 years in Missouri. Besemer says with each significant event, such as the recent devastating earthquake in Haiti, scientists are able to better understand them and draw conclusions about when and why they happen.
Besemer says no one knows when the next one will strike, but that it will be devastating, affecting up to eight states.
“We must ensure that we have the best coordinated response plan in place and are ready to implement it immediately,” Gov. Nixon said. “History has shown that advance planning, coordination and communication between all levels of governments, emergency responders and faith and community leaders is essential in any disaster response. I called this summit to make sure that Missourians get the quickest and most effective response possible in the event of an earthquake.”
For more information on those events and earthquake awareness events go to: www.sema.dps.mo.gov
One of SEMA’s key roles is to maintain the State Emergency Operations Plan (SEOP) that is followed by the Missouri state government departments and agencies when the use of state resources is required. Following the procedures outlined in the SEOP, SEMA coordinates the state’s disaster response for all types of large-scale emergencies. To better prepare for meeting the challenges associated with disasters, SEMA has developed and implemented a number of programs that are designed to mitigate damages, enhance preparedness, improve response operations and aid the recovery process.
A major earthquake centered in the New Madrid seismic zone potentially is one of the most serious natural hazard threats facing the state of Missouri. Experts mostly agree that it is not a matter of if a significant earthquake occurring, but rather it is a matter of how soon one will happen. SEMA has developed a multifaceted earthquake program designed to carry out earthquake awareness and preparedness programs; Work with partners to promote earthquake loss-reduction plans, practices and policies that encourage earthquake mitigation; And develop better response and recovery capabilities through participation in earthquake training and exercises.
About the New Madrid Fault
The New Madrid Fault System extends 120 miles southward from the area of Charleston, Mo., and Cairo, Ill., through New Madrid and Caruthersville, following Interstate 55 to Blytheville and on down to Marked Tree, Ark. It crosses five state lines and cuts across the Mississippi River in three places and the Ohio River in two places.
The fault is active, averaging more than 200 measured events per year (1.0 or more on the Richter scale), about 20 per month. Tremors large enough to be felt (2.5 – 3.0 on the Richter scale) are noted annually. Every 18 months the fault releases a shock of 4.0 or more, capable of local minor damage. Magnitudes of 5.0 or greater occurring about once per decade can do significant damage and be felt in several states.
The highest earthquake risk in the mainland United States outside the West Coast is along the New Madrid Fault. Damaging tremors are not as frequent as in California, but when they do occur, the destruction covers over more than 20 times the area because of underlying geology.
A damaging earthquake in this Area, 6.0, reoccurs about every 80 years (the last one in 1895). In 2002, the U.S. Geological Survey (USGS) released new earthquake probabilities for the New Madrid Seismic Zone. For a magnitude 6.0 or greater earthquake, there now is estimated to be a 25-40% chance in the next 50 years. The results would be serious damage to schools and masonry buildings from Memphis to St. Louis. USGS also estimates a 7% – 10% chance of a 7.5 – 8.0 earthquake in the next 50 years (equal to the earthquake events of 1811-1812).
A major earthquake in this area – the Great New Madrid Earthquake of 1811-12 was actually a series of over 2000 shocks in five months, some of 7.6 intensity and five of which were 8.0 or more in magnitude. Eighteen of these rang church bells on the Eastern seaboard. The very land itself was destroyed in the Missouri Bootheel, making it unfit even for farming for many years. It was the largest burst of seismic energy east of the Rocky Mountains in the history of the U.S. and was several times larger than the San Francisco quake of 1906.
When will another Great Earthquake happen the size of those in 1811-12? Several lines of research suggest that the catastrophic upheavals like those in 1811-12 visit the New Madrid region every 500-600 years. Hence, emergency planners, engineers, and seismologists do not expect a repeat of the intensity of the 1811-12 series for at least 100 years or more. However, even though the chance is remote, experts estimate the chances for a repeat earthquake of similar magnitude to the 1811-1812 New Madrid earthquakes have changed from the1985 estimates of 2.7 – 4.0% probability in 50 years to a 7 – 10% probability. This is a result of new evidence of shorter recurrence intervals identified from pre-historical events. Earthquake probabilities for known active faults always increase with time, because stresses within the earth slowly and inexorably mount, year by year, until the rocks can take no more, and sudden rupture becomes inevitable.
Our Greatest Concerns are the 6.0-7.6 Sized Events, which do have significant probabilities in the near future. Damaging earthquakes of this magnitude are very likely within the lifetimes of our children.
What Can Be Done to Protect Ourselves? Education, planning, proper building construction, and preparedness are proven means to minimize earthquake losses, deaths, and injuries. In recent memory, San Francisco and Armenia both experienced 6.0-7.1 magnitude quakes. San Francisco was prepared; Armenia was not. San Francisco suffered 67 deaths and less than $7 billion in property losses. Armenia had over 25,000 deaths and lost more than $20 billion. More recently, Alaska underwent a 7.9 earthquake. Losses were minimized in this event because the epicenter was in a remote location. Missouri and the Midwest are more prepared than Armenia, but only partly as prepared as San Francisco, and the epicenter is not likely to be in a totally isolated area.
What is the Richter Scale? The Richter scale of earthquake magnitude is a measure of the energy released at the source of an earthquake deep within the earth. It is determined by measuring the amplitudes of ground motion on seismograms. An earthquake has a fixed amount of energy and only one Richter magnitude.
How Much Increase in Energy Does Each Unit of the Richter Scale Represent? It is incorrect to say that each unit of the Richter scale corresponds to a tenfold increase in energy. Each unit, say from 5.2 to 6.2, actually represents 31.6 times difference in energy release. Every two units represent 1,000 times more energy, and every two-tenths of a unit represents double the energy.
The New Madrid Fault is a complex zone of seismically active fractures in bedrock buried several thousand feet beneath river sands and mud. An earthquake’s severity is greatest at its focal point, known as the epicenter, but lessens as the distance from the epicenter increases. The hachured areas on the map above show possible damage levels of a 7.6 earthquake event. The darkest area on the map portrays an epicenter, potentially the area of greatest damage.
If a Fault Has Lots of Little Earthquakes, Will Larger Ones Be Prevented? The answer is, “No”. A magnitude 6.0 (which is damaging) is 1,000 times more energy than a 4.0 (which is not damaging). An 8.0 (which is devastating) is 1,000 times larger than a 6.0. In other words, a fault would have to have 1,000 4.0 events to prevent the occurrence of a single 6.0, or a million 4.0 events (1,000 times 1,000) to prevent a single 8.0.
We Have a Choice. While we still have time, we can get ready and cut our losses, or we can do little or nothing and be caught unprepared. We cannot prevent the coming of an earthquake – it will happen – but we can prevent it from being a major disaster.