Can animals sense earthquakes?
Can animals sense earthquakes? I've heard stories about cats carrying their litter of kittens out of a building just prior to a quake. Is there any truth in it? We've had two quakes in the last three hours, and my goldfish didn't do a thing.
Of course animals can sense earthquakes. Human beings can sense earthquakes. Some years ago a friend of mine in California walked out the door and saw the parking lot in front of him rippling like a flag in a stiff breeze. Without hesitation he concluded: This is an earthquake. The real feat would be sensing a quake an appreciable time in advance. Scientists haven't given up hope of finding animals capable of this, with a view to figuring out how to do it themselves. But so far it's been a slow job.
The idea that animals act funny before an earthquake hits has been out there for thousands of years. However, even if we accept that it's not out of the question, we have to ask: How would this work? What would the animals be picking up on? Some possibilities, as discussed in a 2000 article in the Bulletin of the Seismological Society of America:
- P-waves — the fast-traveling primary seismic waves that show up just before things start getting tossed around. Humans aren't good at sensing these, but animals might be. "Numerous observations exist of animals displaying panic in the few seconds prior to the onset of strong ground shaking . . . including dogs barking, nervous cats jumping out of windows, birds screaming, rats running out of their holes, bees swarming, etc.," we read. Obvious problem: all a few seconds gives you is a head start on freaking out.
- Ground tilt, which supposedly has been detected hours prior to some Asian quakes. But the tilt angles are microscopic, and thus far there's no hard evidence animals can perceive such tiny shifts.
- Humidity changes. Rising groundwater levels have been detected before some quakes, leading some to conjecture that more moisture would be forced into the air, where animals could notice it. Even in explanation this sounds tortured, and it's hard to imagine how a critter could recognize quake-driven humidity amid normal variation.
- Electromagnetic field fluctuations. A lot of people favor this angle, as it's been proven earthquakes can generate detectable electromagnetic activity right before they happen. ("Earthquake lights," the creepy bluish-white flashes that sometimes appear over fault lines before a quake, may be a related phenomenon.) While land animals seem to be fairly oblivious to electrical activity, fish can be attuned to it, and it's possible magnetosensitive animals such as birds and bees could pick up on it too.
- Low-frequency sound. This one is easy to believe, given how much better animal hearing is than ours. One happenstance observation in the Mojave Desert showed dogs could detect low-frequency "booms" from earthquake aftershocks that a seismometer registered but researchers didn't notice.
For argument's sake let's say it's possible for animals to detect quakes in advance. Do they actually ever do it? Some results:
- A study of lost pet ads in the San Jose Mercury News showed no increase in runaway animals before Bay Area quakes, despite claims to the contrary.
- Researchers in the Mojave who happened to be studying a colony of harvester ants during 1992's Landers earthquake saw no change in the ants' behavior before, during, or after the quake.
- A group of 1,200 observers in California who were supposed to report cases of strange animal behavior made no more calls than normal prior to the Coyote Lake earthquake in 1979, but a rush of calls right after, having apparently re-evaluated what they'd seen before the event. At a nearby animal park some behavior was noted as strange but turned out to be pretty common stuff: a shark that lunged out of the water in a reportedly unprecedented manner actually did so about once a week, and a cougar that was especially grumpy prequake seemed to have been grumpy afterward, too, most likely due to a stomachache.
The most widely cited claim of successful animal earthquake prediction is probably the Haicheng, China, quake of February 4, 1975. Official reports said snakes emerged from their winter burrows and froze to death, birds tried to carry eggs from their nests, cows broke their halters and fled, rats acted drunk, and police dogs howled and misbehaved. Chinese authorities boasted that their forecasting prowess had prevented many casualties. Two problems: Numerous foreshocks a day in advance made it obvious something was brewing. More tellingly, the Tangshan earthquake that struck the same region the following year — killing perhaps 240,000 people — went unpredicted.
None of this has stopped people from trying to draw connections, of course. There's even a Web site, petquake.org, where folks can report whatever batshit antics their pets are up to so anybody who's interested can watch for the next big one. The rest of us will just keep an eye out for foreshocks, rising groundwater, and creepy blue lights.