Birds flew erratically above snow-capped buildings. Dogs howled loudly. Then, a devastating earthquake in Turkey and Syria leveled buildings and killed more than 21,000 people.
There is scientific research that supports it. Much in the same way that seismological machines can pick up tremors undetectable to the human body, animals are better equipped to sense tiny foreshocks traveling through the Earth seconds before more powerful earthquake waves barrel through, scientists say. They might even be able to sense them before the foreshocks, some researchers say.
According to the U.S. Geological Survey, abnormal animal behavior in the seconds preceding an earthquake is explained by the difference between two forms of seismic waves. Primary, or P, waves are the first to be emitted from an earthquake, traveling at several miles per second from the epicenter. These are more noticeable to animals, USGS says. P waves are followed by stronger secondary, or S waves, which shake the ground in a rolling motion.
“Very few humans notice the smaller P wave that travels the fastest from the earthquake source and arrives before the larger S wave,” the USGS guidance states. “But many animals with more keen senses are able to feel the P wave seconds before the S wave arrives.”
Initial tremors, detected and analyzed by seismology machines, are also used by early-warning systems to forecast earthquakes — usually with less than a minute of warning. But can animals sense earthquakes even earlier, and better than modern machines? While humans for millennia have anecdotally observed animals seeming to detect earthquakes minutes or hours before they struck, the science is murkier.
One researcher says animals may be able to sense earthquakes even before their foreshocks. “We have a very good indication that animals really feel the precursors of earthquakes, and it’s not seismic activity,” Martin Wikelski, a director at the Max Planck Institute of Animal Behavior who led a study on this topic, said in a telephone interview Tuesday.
In his peer-reviewed study published in 2020, researchers attached electronic tags to cows, dogs and sheep on an Italian farm to observe their movements over several months when earthquakes were detected nearby. They found that the animals were unusually “superactive,” defined as continuously moving for more than 45 minutes, before seven of the eight major earthquakes detected nearby. The research, conducted with devices that Wikelski described as “basically little cellphones for animals,” suggested that the animals may be able to detect earthquakes potentially more than 12 hours before humans — well before any foreshocks.
The reasons animals reacted unusually are not yet clear, he said. “There are indications that they can tell us something. How they do it, we don’t know yet,” he said. He believes that their ability to sense danger may be related to their ability to communicate with each other.
“The cows initially just froze — they didn’t move at all. And then that got the dogs really nervous, and they started to go crazy, barking. And then the sheep went crazy. And that started, altogether, to make the cows really crazy.”
In Wikelski’s study, animals may have been able to detect earthquakes in advance up to 12 miles from their epicenter, he said. He intends to do more research, potentially into whether the farm animals were reacting to iron levels released in the air by underground pressure.
“There are other factors that these animals seem to grasp — but that is still a black box,” Wikelski said.
However, a 2018 review into 700 recorded claims of abnormal animal behavior before earthquakes called for more evidence before drawing conclusions. Researchers focused on the question of whether animals could have the ability to detect earthquakes before seismic machines. Many historical examples of animals behaving strangely could be explained by seismic foreshocks seconds before the bigger earthquake waves, the scientists behind the 2018 review suggested. Much of the existing evidence, they also noted, was too anecdotal and retrospective to be reliable.
There are other high-profile examples, though, from history and the present. One of the earliest anecdotal accounts, attributed to the Roman writer Aelian, details how mice, snakes, centipedes and beetles fled the city of Helike before it was razed by an earthquake and destroyed by a tsunami in 373 B.C.
In 2016, 15 minutes before an earthquake struck Oklahoma, birds took flight in such significant numbers that thousands of them could be observed airborne by radar technology.
Pranshu Verma contributed to this report.