Inspired by this year’s Bay Area ShakeOut, I found myself in the process of preparing my home for a major earthquake, (i.e. obtaining food, water, a first aid kit, a flashlight with extra batteries, a portable radio, fire extinguisher, etc.) when for whatever reason, my dog began to bark erratically. Immediately, the question came to mind: Can man’s best friend, or any animal for that matter, predict an earthquake?
The belief that animals can predict earthquakes has been around for centuries. For example, in 373 B.C., historians recorded that animals, including rats, snakes and weasels, deserted the Greek city of Helice in droves just days before an earthquake devastated the place. In 1975 Chinese officials ordered the evacuation of Haicheng, a city with one million people, just days before a 7.3-magnitude quake based in part on the observation of strange antics of animals (i.e. catfish moving violently, bees leaving their hive in a panic, horses stampeding, snakes emerging from their underground dens in the dead of winter, and caged birds becoming restless). As a result, only a small portion of the population was hurt or killed and… if the city had not been evacuated… it is estimated that the number of fatalities and injuries could have exceeded 150,000.
Before the 1989 Loma Prieta earthquake, countless pet owners in the Bay Area claimed to have witnessed their dogs acting strangely before the ground shook (I.e. barking or whining for no apparent reason) while in September 2003, a medical doctor in Japan made headlines with a study that indicated erratic behavior in dogs, such as excessive barking or biting, could be used to forecast quakes.
In April 2009, British researchers were studying the common toad at a breeding site in central Italy when they “observed a mass exodus of toads." as Jill Lawless reports for the Associated Press. Just five days later, a 6.3 earthquake hit the region, killing some 150 people and causing extensive damage to the town of L’Aquila. Rachel Grant, a researcher at Open University and lead author of one of the first studies to document animal behavior surrounding earthquakes, believes “that toads were able to detect pre-seismic cues such as the release of gases and charged particles, and then used those cues as a form of earthquake early warning system.” According to the study, “Predicting the unpredictable; evidence of pre-seismic anticipatory behavior in the common toad." the toad population at the breeding site dropped to zero three days prior to the quake. “A day after the earthquake, they all started coming back,” Grant told the AP. Because earthquakes are a sudden phenomenon, seismologists have no way of knowing exactly when or where the next one will hit. An estimated 500,000 detectable quakes occur in the world each year. Of those, 100,000 can be felt by humans, and 100 cause damage. But precisely what animals sense, if they feel anything at all, is a mystery.
One simple explanation for unusual animal behavior seconds before humans feel an earthquake is clear: Very few humans notice the smaller P wave that travels fastest from the earthquake source and arrives before the larger S wave while at the same time, many animals with more keen senses are able to feel the P wave seconds before the S wave arrives. But, when it comes to a certain animal species sensing an impending earthquake days or weeks before it occurs, that remains another story and thus, American seismologists remain skeptical. In fact, the United States Geological Survey, a government agency that provides scientific information about the Earth, says a reproducible connection between a specific behavior in animals and the occurrence of a quake has never been made.
Ironically, scientists at Stanford University discovered that strong low-frequency radio emissions preceded the 1989 Loma Prieta earthquake and… because radio waves travel 5,000 times faster than seismic waves… if a radio wave “signature” can be found, it might prove to be invaluable in devising an earthquake early warning system in the future.
Alas, the next time your pet begins to exhibit unusual behavior for no apparent reason, you might want to consider whether he or she has been watching way too many episodes of “Lassie” or else… brace yourself for the big one.
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