According to the Geological Survey of Alabama (GSA), recent seismograph records indicate that earthquakes are more frequent. However, they are often not strong enough to be felt by people on the land’s surface. But the GSA warns that an earthquake can occur anywhere, anytime in Alabama, as the state is strategically located in the Eastern Tennessee Seismic Zone and is under the influence of the lower Mississippi River area’s New Madrid Seismic Zone and the South Carolina Seismic Zone, with varying degrees of danger to Alabama.
As recently as Feb. 18, a magnitude 3.5 earthquake with an epicenter at Fort Morgan at the mouth of Mobile Bay shook southern Alabama and was felt more than 200 miles away. (A 5.0 magnitude earthquake shockwave is equivalent to the explosion of about 400 tons of TNT.)
Ten days earlier, the USGS measured a magnitude 2.2 earthquake near Southside, in the Gadsden area. There were no reports of damage or injury.
In May 2010, a powerful magnitude 3.2 earthquake was recorded in Etowah County.
Do you have earthquake insurance?
With Alabama’s location in one of the most active earthquake areas in the southeast, seismographs record hundreds of tremors a year.
Most of these are not felt on the surface, but about once a year a strong quake may be felt in the state.
Generally, earthquake damage in Alabama is limited to cracked foundations, bricks toppled from chimneys and muddy tap water.
Although earthquake insurance is available in Alabama, it is not automatic.
“You have to ask for earthquake insurance and pay a higher premium for the add-on,” explained Kristi Upton at Jacksonville’s Calhoun County Insurance Center.
Threats from the New Madrid fault
It is the New Madrid Seismic Zone that concerns scientists today. It lies within the central Mississippi Valley, and extends from northeast Arkansas through southeast Missouri, western Tennessee and western Kentucky to southern Illinois. A major quake could be disastrous for Memphis and St. Louis, and well as cause significant damage in northern Alabama, according to FEMA.
An earthquake along the New Madrid fault could kill tens of thousands, or even hundreds of thousands of people, according to Dr. Irwin Redlener, director of the National Center for Disaster Preparedness at Columbia University, who spoke recently to the New York Times.
There is a 90 percent chance of an earthquake of magnitude 6.0 or greater in this area by the year 2040, according to FEMA.
Several of the biggest earthquakes in U.S. history occurred along the New Madrid fault in the winter of 1811-12. They were felt as far south as the Gulf of Mexico, and as far north as Canada. The quake caused eruptions of sand, triggered landslides and permanently changed the landscape.
In 2011 and 2012, several events will mark the bicentennial of the New Madrid earthquakes.
The New Madrid fault line will also be the subject of the first national level emergency earthquake exercise from May 16-20. It will involve officials in eight states: Alabama, Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri and Tennessee.
The biggest earthquake in Anniston
The most severe earthquake ever recorded in Anniston shook the city on the evening of May 5, 1939.
The next day’s Anniston Star featured a front page story with the headline: “Calhoun Earth Tremor Shakes Homes, Stores; Folk Run Into Streets!”
This strong earthquake was a Category V intensity on the old Modified Mercalli scale, about a magnitude 3.5 on the Richter scale. It struck the city at 9:45 p.m., driving residents out of their homes and swamping the telephone exchange.
A state geologist blamed the tremor on slate and marble plates beneath Anniston suddenly sliding along a fault line.
The Star reported that a characteristic thunderous roar accompanied the earthquake, and that “a group of customers in a roadhouse on Horseblock Mountain Road in the vicinity of Chulafinnee were frightened by the tremor and rumbling sound.”
Meanwhile, “patients at the Susie P. Stringfellow Hospital were startled over the shock and it was reported the tremor caused beds to move there.”
Local earthquake disaster plans
The Northeast Alabama Regional Medical Center (RMC) in Anniston has a standardized disaster plan for catastrophic events. According to George Dudchock, the hospital’s emergency preparedness coordinator, RMC has assessed a moderate level of risk for an earthquake event in the Anniston area.
By comparison, a fire inside the hospital has the highest life threat risk factor.
In the event of a significant earthquake, the emergency procedures for fire, severe weather, tornados and traumatic mass casualties would guide the actions of first responders and hospital personnel.
In cases of extreme and widespread destruction and injuries, the Alabama Department of Public Health is prepared to deploy up to seven 50-bed mobile hospital units to afflicted areas. Each unit is stocked with enough supplies for 50 patients for seven days, according to Robbie Stubbs, EP Coordinator for Public Health Area VI in Anniston.
An earthquake preparedness plan
While serious earthquakes are rare in Alabama, the Emergency Survival Program (ESP) has created seven steps as a guide to earthquake preparedness:
• Make a disaster kit.
• Make sure your house is structurally safe.
• Check for injuries and damages.
• Communicate and recover.
Details are available at earthquakecountry.info.
In addition, FEMA offers information and advice on what to do before, during and after an earthquake at: fema.gov/hazard/earthquake.
Recent Alabama quakes
Recent significant Alabama earthquakes include:
• A magnitude 2.9 tremor registered near Jasper at the southern edge of the Bankhead National Forest, 40 miles southwest of Cullman, on Oct. 29, 2010.
• A much larger earthquake struck near Alabaster on April 21, 2009. The magnitude 3.8 quake could be felt in Birmingham. The source of the tremor was 8.8 miles below the intersection of Highways 5 and 219. Although the force of the earthquake equaled the explosion of about 300 tons of TNT, no damage or injuries were reported.
• The most impressive Alabama earthquake in the past 10 years happened eight miles east-northeast of Fort Payne during the early morning hours of April 29, 2003. The magnitude 4.9 tremor shook 13 states in the eastern U.S. as far north as Indiana.
The shaking from the Fort Payne earthquake lasted from 10 to 45 seconds and tied a Knoxville, Tenn., seismic event in 1973 as the strongest earthquake ever recorded in the Eastern Tennessee Zone.
Damage in northern Alabama included a 29-foot-wide sinkhole northwest of Fort Payne, disrupted local water supplies, chimney damage, broken windows and cracked walls. The primary earthquake was followed by several magnitude 2.0 aftershocks, generally too weak to be experienced by anyone on the land’s surface.
Alabama’s biggest earthquake
The largest known earthquake in Alabama happened in October 1916, in northern Shelby County, according to the GSA’s website. The quake, with an intensity level of VII on the Modified Mercalli scale, or magnitude 5.1 on the Richter scale, occurred east of Birmingham along an unnamed fault near Easonville in the Irondale area. The quake was felt in seven states and covered 100,000 square miles.
Damage included toppled chimneys, broken windows and destruction of badly shaken frame buildings. No injuries or deaths were reported.
A GSA computer analysis shows that an earthquake of equal strength hitting the same area today would cause scores of deaths and injuries and more than $1 billion in damages.
The Great ShakeOut
On April 28, the Central U.S. Earthquake Consortium, a group of states that includes Alabama, is sponsoring the 2011 Great Central U.S. ShakeOut. The ShakeOut is an online earthquake preparedness exercise in cooperation with the USGS, FEMA, the American Red Cross and other disaster agencies. To join in this year’s event, sign up at www.shakeout.org/centralus.
A survivor’s account
Experiencing a catastrophic earthquake is a lifetime traumatic event for survivors. Actor Brian Houlihan has written about how he and his wife Tasha lived through the magnitude 6.7 earthquake that struck the Los Angeles area on Jan. 17, 1994. More than 50 people were killed and 8,700 injured. The quake caused an estimated $20 billion in damages.
“The most significant thing about it was that it seemed to last a very, very long time,” Houlihan writes. (The actual duration of the quake was 45 seconds.) “I considered the possibility that the U.S. was under nuclear attack!”
Houlihan and his wife were awakened by the quake at 4:30 a.m. They survived by huddling under the door frame of their bedroom as furniture, dishes and building material crashed down around them.
“The scariest experience was the utter silence that followed the earthquake. The power was out. We were in the dark, and there was not a sound.”
Woken up by an earthquake
Since nearly all the earthquakes in Alabama have magnitudes of 2.0 or lower, most of the state’s residents will never feel the numerous tremors. However, there is always the possibility of being awakened in the night by the shiver of the earth suddenly and unexpectedly shifting ground. It happened to Anniston area resident Mary Keller.
The sound of rattling dishes and shaking lamps brought her awake with a start. “The vibrations lasted for quite a time, maybe 10 to 20 seconds.
It was enough to wake me up. The tremors passed, and I went back to sleep,” she said. In the morning, television news featured a story about a powerful earthquake in Fort Payne, 60 miles to the northeast.
Art Gould is a former newspaper reporter and book publisher. He lives in Anniston.
Get started on a family disaster kit. Items to include:
* Water—one gallon per person, per day (3-day supply for evacuation, 2-week supply for home)
* Food—nonperishable, easy-to-prepare items (3-day supply for evacuation, 2-week supply for home)
* Battery-powered or handcrank radio (NOAA weather radio, if possible)
* Extra batteries
* First aid kit
* Medications (7-day supply) and medical items
* Multipurpose tool
* Sanitation and personal hygiene items
* Copies of personal documents (medication list and pertinent medical information, proof of address, deed/lease to home, passports, birth certificates, insurance policies)
* Cell phone with chargers
* Family and emergency contact information
* Extra cash
* Emergency blanket
* Map(s) of the area
For more information and suggestions for your disaster kit, visit www.redcross.org.
— Red Cross