Some animal species can sense earthquakes just before they happened. How is this even possible? Scientists have an answer for us.
Researchers around the world continue to study animal behavior in relation to the occurrence of natural disasters and hope that these studies will help predict disasters.
For example, a team of NASA researchers has concluded that some animals sense chemical changes in the groundwater before an earthquake strikes.
Researchers began investigating this phenomenon after observing how an entire population of frogs suddenly abandoned their pond days before the 2009 L'Aquila earthquake in Italy.
Before an earthquake occurs, the earth's crust releases electrically charged particles that react with groundwater and surface water. Animals living in these waters or near lakes and rivers are extremely sensitive to the slightest change in water chemistry. In other words, they sense earthquakes days before the tectonic plates move.
Animals That Can Sense Earthquakes: Famous Cases
The frogs in L'Aquila are not the only example of animals sensing an earthquake. There are hundreds of accounts and reports from around the world of the obvious change in animal behavior before earthquakes occur.
A few hours before a powerful earthquake occurred in Italy in 1805, cows began to moo loudly, sheep and goats bleated, dogs howled, and cats began to spit and be extremely agitated. The animals tried to hide. Rabbits and moles left their burrows, fish rose to the surface of the water and could easily be caught, and ants left their burrows and gathered on the surface of the land.
In the winter of 1975, authorities in the Chinese city of Haicheng took account of the unusual behavior of animals and managed to evacuate most of the population the day before an earthquake measuring 7.3 on the Richter scale. Still, 2,000 people died, but the number was much lower than the estimated number if the evacuation had not taken place.
In 1976, in Friuli, the dogs started howling and the cats were very agitated. Shortly afterward the region was hit by an earthquake measuring 6.4 on the Richter scale.
Before the major earthquakes in Northridge, California (1994) and in Turkey and Greece (1999), strange animal behavior was reported. Dogs barked wildly, showed increased aggression, and tried to run away. Cats sought hiding places and birds wanted to escape from cages.
On 26 December 2004, an earthquake in the Indian Ocean caused a devastating tsunami. More than 150,000 people were victims of this natural disaster. There were almost no reports of wildlife casualties in the areas affected by the tsunami. Officials at Sri Lanka's Yala National Park have recorded only a few deaths in the reserve, which is home to hundreds of wild animals. They noted that the animals in the reserve sensed danger and took early refuge in an area of high relief.
The "Bad Omen" Prior To The Sichuan Earthquake
In May 2008, the devastating Sichuan earthquake was similarly reported in advance. But people did not understand the animals' alarm and ignored nature's signals. As early as mid-April, authorities should have been alerted by the disappearance of an entire lake near the town of Enshi, some 500km from the epicenter.
The phenomenon has been known since ancient times: sudden emptying of wells was usually recorded 10-20 days before a strong earthquake.
Then, three days before the earthquake, thousands of frogs invaded the streets of Mianzhu city. Locals alerted the authorities, frightened by this "bad omen" which, according to popular belief, presaged a natural disaster.
The local Huaxi Metropolitan newspaper even devoted an article to the strange phenomenon, but the authorities were quick to calm the situation. Mianzhu has suffered serious losses, more than 2000 casualties.
Animal Species That Can Sense The Upcoming Earthquake
Most medieval chronicles that speak of earthquakes mention that before they happen, some animals behave strangely: dogs howl uncontrollably, cats run and hide, and other creatures show signs of anxiety, each in its own way.
Farmers are the ones most warned because horses, cows, sheep, and chickens feel the tremors. When the whole yard is an "infernal concert", it is clear that "something" is going to happen.
The pigeons don't go into the shelter and fly around disoriented. Pigs, if there are more than one in the same pen, fight each other. Chickens stop laying eggs and become restless. Bees leave the hives without being attacked. Mice come out of hiding, and even ants and cockroaches come out of hiding without fear and migrate at a rapid pace.
Species that can sense earthquakes include fish and snakes. Both species have highly developed sense organs. Snakes sense vibrations and infrared radiation and fish are very sensitive to electric fields. They are therefore likely to sense small changes in the electromagnetic field or small shock waves several days before a strong earthquake.
Studies have shown that very shortly before and during the earthquake, snakes began to struggle. This is unusual behavior because normally all snakes are inactive during the day.
Most interesting is the behavior of the trunkfish, Gnathonemus petersii, which make their home in the waters of the Nile. They show their restlessness by completely changing their behavior 4 days before the phenomenon occurs.
Do Animals Have a "Sixth Sense"?
No, basically, the animals have no sixth sense to predict an earthquake. But they do react to small changes in their environment, such as certain tectonic movements.
Even crocodiles are not insensitive before an earthquake occurs. A Chinese zoologist observed the unusual behavior of crocodiles before an earthquake hit the Japanese island of Honshu. He said the animals were making a sort of growling, nodding, and wagging their tails. A Japanese specialist said they could sense the imminence of an earthquake within a radius of 150km.
Birds and elephants can sense the vibrations of small shocks and ultrasound very well, and rats will immediately feel the high-frequency sounds produced by rocks breaking up inside the earth.
It is known that in 1977, shortly before the Vrancea earthquake, thousands of rats emerged from the basements of blocks of flats, fleeing in terror between the feet of passers-by. Many were frightened and thought the world was coming to an end.
Twelve hours before the catastrophic earthquake of 4 March 1977, many earthworms appeared on the earth's surface, even though there was no rain at the time. Many frozen snakes were found in the fields.
Dogs - The Best Predictors Of Earthquakes?
Another experiment, done before the 2003 Seattle earthquake, showed that the best predictors of earthquakes are dogs, especially those with small heads and pointed ears.
Dogs - especially breeds that are known for their sharp hearing - tend to behave very strangely, as if disturbed by a shrill sound, prior to an earthquake. They bark seemingly for no reason, ask to go outside, and run in no particular direction to get away from the disturbing sound. If they can't escape the irritating area, they become aggressive. In September 2003, a doctor in Japan published a study showing strange dog behavior, such as excessive barking or biting, which could predict earthquakes.
Twenty-four hours before the Seattle earthquake, half of the dogs tested became restless and started barking for no apparent reason.
Of all the mammals in the zoo, red lemurs were the earliest to sense the earthquake. They sounded an alarming sound 15 minutes beforehand.
How Do Cats React Prior To Earthquakes
Cats also get very nervous before an earthquake, meowing and looking for shelter. If danger is imminent they may run around the house in a mad dash, meowing fearfully, even howling, and sometimes becoming aggressive.
Rabbits have extremely keen hearing and have very obvious reactions to earthquakes. Before an earthquake occurs rabbits become restless, stop eating and bump into the walls of their cages in an attempt to escape.
When they sense an earthquake approaching, the birds fly around disoriented and if they are caged they try hard to escape.
During the 26 December 2004 earthquake in the Indian Ocean in Thailand, 12 elephants trained to walk tourists on the beach became agitated and noisy hours before the cataclysm struck. The animals suddenly ran away from the ocean, along with their passengers, heading for higher ground. In doing so, the elephants saved the lives of the tourists they were carrying.
James Berkland, a retired geologist from Santa Clara County, California, says he can predict earthquakes with better than 75% accuracy just by counting lost-animal notices in newspapers and correlating that data with lunar cycles. Berkland says the number of dogs and cats that get lost increases significantly two weeks before an earthquake occurs.
Of course, these are only some reported cases and the conclusions of some scientists, because it is very difficult to rigorously study the behavior of animals in the event of an earthquake, which is virtually impossible to predict.