It has long been suggested that animals often behave differently than usual shortly before an earthquake. According to reports, some wild animals leave their sleeping and nesting places immediately before strong earthquakes occur, and pets such as dogs become particularly restless. Until recently, however, these observations were not based on scientific studies. Moreover, it could not be ruled out that the changes in behaviour are not caused by other factors. So can animals really "predict" earthquakes?
Researchers from Germany's Max Planck Institute (MPI) for Behavioural Biology in Constance/Radolfzell and the Centre for the Advanced Study of Collective Behaviour at the University of Constance have now investigated exactly this. In a region of northern Italy where earthquakes are particularly common, six cows, five sheep and two dogs were equipped with small sensors. With the help of these sensors, the researchers were able to measure whether the animals can actually detect early signs of earthquakes. They were observed over several months, before and during a series of several earthquakes. The measurement data from the sensors provide information about the animals' movements or body position, for example.
How Cows, Dogs and Sheep Sense Coming Earthquakes
The research results were able to confirm the long-standing assumption: "Cows become less active shortly before an earthquake, they virtually freeze. When dogs and sheep see this, they then become nervous and restless," says Martin Wikelski, head of the research project at the MPI. In this sense, the animals are reacting to each others as much as they are to environmental stimuli.
"It's a bit like a stock market crash, and then it rises. With the acceleration patterns we can then see from the animals' energy consumption that they change their behaviour before an earthquake". The data sets were compared with the animals' normal behaviour and the respective daily activity. If it is observed that the animals become particularly active in the middle of the day, when they are usually rather inactive, this may be an indication that an earthquake is about to occur.
How animals "sense" coming earthquakes has not yet been conclusively researched. "It is quite likely, however, that the pressure of the plates that later slide apart during an earthquake is so great shortly before a major quake that rock minerals are released into the air," says Wikelski. The animals should be able to perceive the ionisation of the air with their fur. It is also conceivable that the animals could smell the gases released from quartz crystals before an earthquake. Wikelski explains: "If the epicentre is directly below the animal pen, the advance warning time is around 15 hours. If the epicentre is about 15 kilometres away, it is about two hours". According to Wikelski, these time spans correspond roughly to the speed at which the rock particles spread in the air.
Observation Data as an Early Warning System for Earthquakes
Currently, the observation data of the animals is sent directly to the researchers in Constance via an internet connected receiver on site. Almost in real time - around every three minutes - the researchers receive new data on the behaviour of the animals.
However, in order for the observation data to actually be used for earthquake predictions, the researchers plan to observe an even larger number of animals over longer periods of time and in different earthquake zones around the world. The global observation system ICARUS on the International Space Station ISS will be used for this purpose. This is scheduled to start its scientific operation in a few weeks. Since, according to Wikelski, the available payload on the International Space Station (ISS) is not yet sufficient, the data cannot yet be transmitted to the satellite in real time. To enable natural disasters to be predicted in future with the aid of animal observation data, capacities are now to be expanded.
This is a translation by Mark Newton of an original article that first appeared on RESET's German-language site.