For the second time in two weeks, an earthquake has struck Mexico, leveling sky rises, splitting freeways, and killing over 270 people. The 7.1-magnitude quake that occurred Tuesday afternoon has overwhelmed residents and officials of Mexico City. Located in a region known as the Pacific Ring of Fire, a 25,000-mile U-shaped ring of Pacific coastline that stretches from the Indian-Australian Plate to the South-American Plate, Mexico City is an area that is notoriously at risk for major earthquakes. Linked to 80 percent of global quakes, the Pacific Ring is considered one of the most seismically active areas on the planet.
What Causes Earthquakes and Can They Be Predicted?
An earthquake occurs when massive blocks of the earth’s crust known as tectonic plates, suddenly move past each other, releasing built up pressure and energy in the form of seismic waves. These seismic waves are responsible for making the ground shake. Currently, seismologists have not figured out a way to predict earthquake far enough in advance to avoid the mass casualties that accompany colossal quakes. Though extensive research and scientific support has yet to approve these theories, many suggest that animals have the capacity to foreshadow earthquakes before they occur.
Since the time of ancient Greece, some historians have maintained the belief that animals have the ability to predict the arrival of earthquakes. After a devastating earthquake decimated the Greek city of Heline in 373 B.C, townsfolk reported that snakes, rats, centipedes and weasels were seen fleeing the city in the days leading up to the quake.
Similarly, Chinese officials ordered the evacuation of Haicheng, a city with over one million residents, just days before a 7.3-magnitude quake in the winter of 1975. This order came after a large number of snakes in the area interrupted their hibernation and emerged from their burrows. Normally this surfacing would not be a cause for concern, but winters in Haicheng can be brutally cold and temperatures at this time were below freezing levels. Snakes are cold-blooded reptiles who must maintain a warmer body temperature to survive. During winter months, they tunnel themselves deep within the ground and remain there until spring. As witnesses in Haicheng reported the snakes leaving their burrows and exposing themselves to the frigid cold, officials became alarmed and evacuations began. When the earthquake arrived two days later, a small portion of the population who failed to evacuate were hurt or killed while close to 150,000 evacuees were spared.
Arguments from those who believe that animals have the ability to predict natural disasters rely on the understanding that earthquakes generate electrical fields and magnetic fluctuations. Since many animals have the ability to hear infrasonic sounds like the low rumbling of an onrushing earthquake, it is possible that they can sense a quake before we can. Additionally, changes in the mineral and chemical composition of groundwater have been measured before the onset of a quake. Historically, instances of entire amphibian populations (frogs and toads) abandoning their swampy homes before an earthquake have been reported. In 2010, the Journal of Zoology published a study in which a colony of toads deserted their mating site three days before an earthquake struck L’Aquila in Italy. The toads did not return back to their homes unit the last aftershock hit 10 days later. Studying a pre-quake mass exodus like the one in Italy could help scientists dechipher the connection between animal instinct and natural disaster. However, the US geological survey says there is just not enough evidence to conclusively determine that animals are accurate predictors of a quake well enough in advance.
A New Way Forward
Seismologist Joseph L. Kirschvink suggests that an animal’s instinctual fight or flight response may provide a sort of early warning system for seismic events. Building on his theory, the German-Russian lead project, Icarus (International Cooperation for Animal Research Using Space) uses a satellite-based monitoring system to track the response of mass migrations of birds as they pass through the epicenter of an earthquake. Icarus researchers are counting on migrating birds to cross the path of at least one of the 100 large scale earthquakes that happen each year. If the birds sense the epicenter and re-route their traditional migratory paths away from it, positive evidence that animals have the instinctual ability to foretell the coming of an earthquake can be examined.
Earthquakes can cause serious damage in the homes and lives of the people that you love. If you live in an earthquake zone, you should prepare an earthquake kit and check on its contents every few years.