While we have all been busy trying to get spring activities going, it is easy to forget we are living in an earthquake zone. Unless you are new to the area, everyone has heard of the New Madrid Fault Zone and the danger it contains. The New Madrid seismic zone of southeast Missouri and adjacent States is the most seismically active in North America east of the Rockies. During the winter of 1811-1812 three very large earthquakes devastated the area and were felt throughout most of the Nation.
They occurred a few weeks apart on December 16, January 23, and February 7. Hundreds of aftershocks, some severely damaging by themselves, continued for years. Prehistoric earthquakes similar in size to those of 1811-1812 occurred in the middle 1400’s and around 900 A.D. Strong, damaging earthquakes struck the southwestern end of the seismic zone near Marked Tree, Arkansas in 1843 (magnitude 6.3), and the northeastern end near Charleston, Missouri in 1895 (magnitude 6.6). Since 1900, moderately damaging earthquakes have struck the seismic zone every few decades.
Many times a year people living near the fault feel still smaller earthquakes that do not cause damage. The uptick in the number of small earthquakes over the past several years have many wondering if they are indications that another big quake may be looming. But are there other signs that we can observe that may give an early warning of a big quake coming. Before an earthquake rattles a region, some animals within the vicinity might be able to sense the event just seconds or minutes, even days before it happens.
The earliest reference to unusual animal behavior in response to an impending earthquake dates back to 373 B.C. in Greece, according to the United States Geological Survey (USGS). Several days before a destructive earthquake hit, creatures such as centipedes, snakes and rats reportedly left their homes to find safe locations, according to the USGS. Similar accounts have surfaced in the centuries since, including reports of violently moving catfish, restless or barking dogs and panicked bees abandoning their hives, according to the National Geographic.
Scientists can easily explain the cause of unusual animal behavior seconds prior to humans feeling the jolt of an earthquake, the USGS reported. “Many animals with senses [that are] more keen than humans are able to feel the P wave seconds before the S wave arrives,” said USGS cartographer Diane Garcia. The USGS defines a P wave, or compressional wave, as a seismic body wave that shakes the ground back and forth in the same direction and the opposite direction of the wave’s movement. An S wave, or shear wave, also shakes the ground back and forth, but does so perpendicular to the wave’s direction of movement. Rodents and other urban animals are great at sensing subtle changes and reacting to earthquakes before humans do, according to Jordan Foster, a pest technician with Fantastic Pest Control “Seismic activity creates stress, which releases charged particles up to the Earth’s surface and into the air,” Foster said.
“Those particles transform into ions, which increases the serotonin levels in animals.” When this occurs, creatures such as rats, weasels, mice and squirrels might behave oddly, including standing frozen in place or acting uneasy. “This can happen anywhere from a week to just seconds prior to the actual earthquake,” Foster said. Rodents are also able to detect the primary seismic waves far more in advance than people can, he added. Research has also shown that ants might be able to sense an earthquake coming. In advance of earthquakes with a magnitude of 2.0 or greater, ant colonies have been observed stopping their usual activities prior to, during and up to a day after an earthquake, Foster said.
Ants build up mounds prior to a big quake German researchers found that ahead of an earthquake, red wood ants, which prefer to live along Germany’s active faults, remained awake throughout the night outside their mound, exposed to predators. Such behavior is unusual for ants, as they’re not nocturnal creatures, Foster said. “It’s unclear how exactly they sense the danger, but the two leading theories are that they can feel the changes of Earth’s magnetic field and sense fluctuations in carbon dioxide levels,” he said. Most accounts of animals behaving strangely are anecdotal, and consistent, reliable behavior prior to an earthquake as well as a mechanism explaining how it might work still elude scientists, the USGS reported.
Although animals may be able to detect an earthquake seconds before the first tremor, sensing an earthquake days or weeks before it happens is a different story, according to Garcia. “Much further research needs to be done regarding the possibility of genetic systems having evolved enough to have early warning behaviors for a seismic event,” she said. Some, like Robert Williams at the U.S. Geological Survey in Colorado, worries that time may not on our side. By studying remnants of the 1811 quake, scientists say they have determined that this region suffered similar powerful upheavals in about 2350 B.C., 900 A.D. and again in about 1450.
To some, this indicates that this area has a history of massive earthquakes and that we’re already 200 years out from the last one. “We can’t predict earthquakes,” Williams told National Public Radio in 2011. “So the geologic record is really the strongest piece of evidence we have to remain concerned about earthquakes in the New Madrid region.” Hopefully a big earthquake like the ones in 1811 and 1812 will not happen until the distant future. But we can’t depend on that. So the best course of action is preparedness. Have a plan for the best course of action to ensure your family’s survival if the worst happens. The time to start is now. Have a plan for you and your family’s survival