Study aiming to solve age-old mystery shows that animals exhibit strange behavior up to 20 hours before a quake hits.
RADOLFZELL, Germany – According to anecdotal accounts, farm animals and pets often behave abnormally in the hours leading up to earthquakes. However, these findings have not been supported by scientific evidence. At least not until now.
A new study by German scientists provides scientific evidence to support claims of odd animal behavior prior to earthquakes. The research suggests that animals may indeed provide valuable clues to when and where earthquakes will occur.
Tracking animals movements before earthquakes
In the study, researchers attached movement tracking devices to farm animals in an earthquake-prone area of Northern Italy. These tracking devices, known as accelerometers, were attached to the collars of six cows, five sheep, and two dogs. All of the animals had been previously observed acting abnormally before earthquakes.
After attaching the accelerometers, researchers recorded the animals’ movements for several months. Throughout that period, approximately 18,000 earthquakes were reported in the region. Many of these earthquakes were weak and barely noticeable, but 12 of them were strong (4 or higher on the Richter scale).
The researchers chose to look at only the earthquakes that triggered statistically significant earth movements on the farm. The epicenters of these earthquakes ranged in distance from the farm. Some were very close, while others were up to 28 kilometers (17.4 miles) away.
Statistical models based on financial econometrics were used to analyze the data recorded from the accelerometers (i.e., body acceleration data). By using this data and marking periods of unusual activity using statistical criteria, the researchers were able to objectively define what constitutes as “odd” animal behavior.
“Because every animal reacts differently in size, speed and according to species, the animal data resemble data on heterogenous financial investors,” explains co-author Winfried Pohlmeier in a media release. Pohlmeier is a professor of Econometrics at the University of Konstanz and a principal investigator at the Centre for the Advanced Study of Collective Behaviour.
Proximity to quakes matters
Unusual animal activity patterns were indeed recorded among the farm animals up to 20 hours before earthquakes occurred. Further, the strange behaviors depended on how close the animals were to the epicenter of the earthquake.
“The closer the animals were to the epicenter of the impending shock, the earlier they changed their behavior. This is exactly what you would expect when physical changes occur more frequently at the epicentre of the impending earthquake and become weaker with increasing distance,” says Martin Wikelski, director at the Max Planck Institute of Animal Behavior. He’s also a principal investigator at the Centre for the Advanced Study of Collective Behaviour.
Interestingly, this effect was apparent only when the researchers looked at all the animals, not just individuals ones. “Collectively, the animals seem to show abilities that are not so easily recognized on an individual level,” says Wikelski.
Mystery behind behavior still remains
It is still unclear what triggers unusual behavior in animals before earthquakes strike. One possibility is that animals are able to sense air ionization caused by large changes in rock pressures with their fur. Alternatively, animals may be able to smell gases released from quartz crystals prior to earthquakes.
Regardless of how animals can sense impending earthquakes, these findings are promising for future predictions. In December 2019, the researchers tested the predictive abilities of animal accelerometer data and were indeed able to predict an earthquake.
Before the method can be used to reliably predict earthquakes, however, researchers need to record data from more animals over longer time periods in different areas around the world. To do this, the researchers want to use the global animal observation system known as Icarus. Icarus is a joint project funded and carried out by the German Aerospace Center (DLR) and the Russian space agency Roskosmos and is supported by the European Space Agency (ESA).
The study is published in Ethology.