Can animals warn of earthquakes?

A new study tried to check whether animals can actually sense earthquakes before they happen and whether this can be used to prepare for an emergency ahead of time

Liron Dana, Angle - news agency for science and the environment

In the days before the devastating earthquake in eastern China in 1976, Large numbers of animals were observed (snakes and mice, among others) that leave their dens in the middle of winter. Such cases have caused many to believe that animals have a sixth sense that warns them of natural disasters ahead of time. But until now there were no serious data on the subject.

Now, researchers at Max Planck University in Germany believe they have a solution to the question of whether animals can be used as indicators of earthquakes. In their opinion, their research may help overcome the great human difficulty in early prediction of earthquakes.

This is a very serious matter. In 2004, for example, they died all over the world About 300 thousand people Following earthquakes and in 2010 about 230 thousand people. In the United States alone the earthquake damage are undervalued by an annual amount of 4.4 billion dollars.

However, and despite more than a hundred years of research in the field, today the maximum warning range against an earthquake is only a few seconds to a few minutes. Most researchers use means that measure the oscillation of seismic waves reflected from the earth's interior. These measures, as advanced as they are, have so far failed to provide effective prediction.

"In the early stages of an earthquake's formation, the seismic radiation is absorbed by the earth's rocks, it is not possible to receive signs that indicate a movement below the surface until a very late stage, so the warning time is short," says Prof. Dov Bhatt, from the Department of Earth Sciences at Ben Gurion University. "In order to prevent damage to people and property, the ambition is to extend the warning time to at least a few hours."

Feel the next tremor

In the German study, recently published in the journal Ethology, the researchers checked whether the behavior of animals changes before the occurrence of an earthquake. A team of researchers arrived at an isolated farm in central Italy, in an earthquake-stricken area, and installed motion sensors on sheep, cows and dogs. The sensors recorded the daily movements of the farm animals over several months, during which thousands of earthquakes of various intensities occurred.

Throughout this period, sharp and rapid changes in the movement patterns of the animals were recorded, revealing extreme changes in their behavior patterns within a few hours before earthquakes. From the analysis of the results and their comparison with seismic data, it was discovered that warnings were also received for moderate and weak tremors. Also, the closer the animals were to the epicenter, the earlier they recognized and warned about the underground movement.

The record early warning time for the tremor was 20 hours, and it was achieved when the animals were in a closed stable and not in an open area. According to the researchers, staying inside a closed structure may highlight the anxiety experienced by the animals on the farm. Furthermore, the preliminary behavior change of the animals was significant only when the researchers observed the collective behavior of the sheep, cows and dogs together.

"Stress behavior in a certain species triggers stress behavior in other species. When it comes to life-threatening situations, intersex communication is very strong and reading the signs between the different sexes pays off." Dr. Ron Chen, a behavioral and quantitative ecologist, explains. "Even when different species do not know how to identify the source of stress, it is still worthwhile for them to enter an emergency mode to maintain vigilance and pass on the information about a dangerous factor."

As of today, an earthquake prediction system based on animal behavior is still far from being reliable and accurate and it is necessary to research and collect many more data from different regions and from other animals. However, there is no doubt that the results point to the animals' intriguing predictive abilities and raise questions about the mechanism behind their "sixth sense".

According to previous studies, the prevailing theory is that in the initial phase of the formation of an earthquake there is a high pressure between rocks in the subsoil which causes for the release and dispersion of electric charges To their environment and the air above them, it is likely that the animals sense the change in the electric charge of the air and react accordingly.

Electromagnetic radiation measurement

Due to its location on the Syrian-African rift, Israel is a focus for future earthquakes. "In Israel, strong earthquakes appear in cycles of one hundred years. Catastrophic earthquakes have occurred in Safed and Sinai in the past centuries, and in the coming decades an earthquake of a similar magnitude is expected to occur," says Bhatt.

Researchers from Ben Gurion University, headed by Bhat, Prof. Avinam Rabinovitch and Dr. Vladimir Fried, are currently working on a study that will test a system for predicting earthquakes by measuring electromagnetic radiation near the Dead Sea rift. In the initial stage of earthquake development, the electromagnetic radiation is returned to the surface in a certain pattern of signals. The researchers found that a small displacement below the surface is enough to detect a repeating pattern of signals that characterizes an earthquake. Similar to relying on animals for early warning purposes, this research may also provide prediction hours or even days before the earthquake turns deadly.

Considering the interesting results of the study conducted in Italy, the day may not be far when a similar system will be tested in Israel as well. "The main difficulty in conducting the research is analyzing a large amount of data, but the costs of the technological equipment are not high," says Chen. "It definitely makes sense to conduct this kind of research in Israel as well, since animals give us information that our best devices cannot provide."

More of the topic in Hayadan:

• The earthquake that destroyed the Canaanite palace in Tel Kaberi from 3700 years ago
• Oil and gas extraction from oil shale causes man-made earthquakes
• Dr. Avi Shapira, Chairman of the Interministerial Steering Committee for Earthquake Assessments warns against unpreparedness
• How do you protect the houses from earthquakes?