Even today, nobody can reliably predict when and where an earthquake will occur.
However, eyewitnesses have repeatedly reported that animals behave unusually before an earthquake.
In an international cooperation project, researchers have investigated whether cows, sheep, and dogs can actually detect early signs of earthquakes.
To do so, they attached sensors to the animals in an earthquake-prone area in Northern Italy and recorded their movements over several months.
Results show that:
- The movement data show that the animals were unusually restless in the hours before the earthquakes.
- The closer the animals were to the epicenter of the impending quake, the earlier they started behaving unusually.
In conclusion, the movement profiles of different animal species in different regions could therefore provide clues with respect to the place and time of an impending earthquake.
18,000 earthquakes and 13 sensitive animals
On an Italian farm in an earthquake-prone area, the scientists attached accelerometers to the collars of six cows, five sheep, and two dogs that had already displayed unusual behavior before earthquakes.
The researchers then recorded their movements continuously over several months.
During this period, official authorities reported about 18,000 earthquakes in the region. In addition to many small and hardly noticeable quakes, there were also 12 earthquakes with a strength of 4 or higher on the Richter scale.
Unusual behavioral patterns before an earthquake
After statistical analysis of all data, researchers discovered unusual behavioral patterns up to 20 hours before an 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 epicenter of the impending earthquake and become weaker with increasing distance.
However, this effect was clear only when the researchers looked at all animals together. “Collectively, the animals seem to show abilities that are not so easily recognized on an individual level.“
Earthquake early warning system
It is still unclear how animals can sense impending earthquakes.
Animals may sense the ionization of the air caused by the large rock pressures in earthquake zones with their fur. It is also conceivable that animals can smell gasses released from quartz crystals before an earthquake.
However, before the behavior of animals can be used to predict earthquakes, researchers need to observe a larger number of animals over longer periods of time in different earthquake zones around the world (search for project Icarus on ISS).