Can animals detect earthquakes early?
Videos have emerged of animals acting strangely before the devastating earthquake that struck Turkey and Syria last week.
The footage appears to show dogs barking and birds flying irregularly in the lead-up to the tragedy, which has killed more than 33,000 people.
People often report abnormal behaviour from animals in the lead up to earth tremors.
But is there any science behind this ‘sixth sense’ - and what does the research say?
Have animals detected earthquakes early in the past?
Around 500,000 detectable quakes occur in the world each year, of which roughly 100 cause damage. Seismologists have no way of knowing exactly when or where the next earthquake will hit - so the potential for animals to be early-warning systems is interesting .
But the idea that animals can predict earth tremors is not new. In 373 BC, Roman author Aelian wrote about how snakes, mice and insects fled the city of Helike before it was destroyed by an earthquake.
More recently, hibernating snakes abandoned the Chinese city of Haicheng prior to a 7.3 magnitude earthquake in 1975. In 2016, thousands of birds took flight before an earthquake struck Oklahoma.
Animals might sense earthquakes seconds early
Science suggests that animals may be able to sense initial tremors seconds or minutes early.
When an earthquake hits, seismic waves emanate out from the tremor epicentre.
Primary waves - the first waves to be felt - are smaller, and go largely undetected by humans. They precede more violent secondary waves, which can shake the ground and topple buildings.
Animals - who have more acute senses of hearing and smell than humans - may feel these seconds or minutes before humans.
Elephants and birds, for example, might feel the low frequency sound waves and vibrations from weak foreshocks. Whereas rodents can hear the high frequency sounds that emanate from shattering rocks.
It’s unlikely that animals can sense earthquakes far in advance
But could animals sense earthquakes early enough to act as an ‘early-warning’ system?
Research suggests it’s unlikely.
A 2018 Bulletin of the Seismological Society of America review examined 180 previous studies and found that the correlation between animal behaviour and earthquake tremors was largely anecdotal.
“The study clearly demonstrates strong weaknesses or even deficits in many of the published reports on possible abnormal animal behaviour,” the authors wrote.
Subsequent research has been more promising.
In 2020, researchers from the Max Planck Institute of Animal Behavior recorded the movements of north Italian farm animals over several months.
They found that the animals were unusually agitated in the hours preceding the earthquakes.
“The movement profiles of different animal species in different regions could … provide clues with respect to the place and time of an impending earthquake,” the researchers wrote.