Every time there is a tsunami, we hear about animals fleeing to high ground and avoiding death. I've read some articles that suggest ELF/VLF sensitivity warns the animals, as they can effectively "hear" the earthquake. Any truth to that?
In a study done in April 2000 by Joseph L. Kirschvink (PDF File), the final conclusion said that there may be some evolutionary selective pressures for some animals to develop such a trait, but the evidence is anecdotal at best.
Wisegeek would also seem to support that the issue isn't settled, but that the main impetus for this idea is anecdotal as opposed to truly evidence based.
The idea that animals can sense earthquakes is a popular one, and anecdotal stories about animals behaving strangely before major earthquakes have been told for centuries. However, debate over whether or not animals can truly sense earthquakes has not resolved the question, despite research in several earthquake-prone regions of the world. Some researchers believe that animals can, in fact, sense earthquakes, because they are more susceptible to subtle environmental changes than humans are. Others, however, argue that there are numerous causes for strange animal behavior, and that there many be a human psychological aspect involved in claims that animals can sense earthquakes.
Support for the idea that animals can sense earthquakes includes studies which suggest that animals may be able to sense vibrations before humans do. Animals have been proved to be more sensitive to ultrasonic waves such as the weaker p-waves which precede a major quake. It is possible that animals can sense an earthquake a few seconds before people do. In rare cases, an earthquake may be preceded by foreshocks, which may not be detectable by humans without specialized devices, but could be felt by animals. Other researchers have suggested that animals may sense chemical or electrical changes in the field of the Earth which could be indicators of an earthquake.
The 2011.03.30 episode of Freakonomics Radio, "Why Can't We Predict Earthquakes", discusses prediction of earthquakes with Bill Ellsworth, a geophysicist at the United States Geological Survey in Menlo Park, Calif. Starting around 9:40:
Ellsworth: We had a project that had a group of volunteers that had animals that were very sensitive to the coming of earthquakes. And the instructions were that when their animals were acting up they were to call up this number. There were never any messages left before earthquakes, but lots of messages left after earthquakes-- Oh they had meant to call but they didn't.
Host: So in other words, "Moments before the earthquake I noticed that my cat was pacing back and forth"?
Ellsworth: That's the kind of thing. Exactly.
This is pretty strong empirical evidence that animals (or at least domesticated American animals) have no such ability. It seems more likely that confirmation bias is at play here: unusual animal behavior that would normally be discounted might be interpreted differently if it occurs just before an earthquake.
As far as I can tell, the evidence available is sketchy at best. No controlled studies have been performed, which is unsurprising given the general difficulty in predicting earthquakes at all. One would think that if it were known that animals were able to predict earthquakes significantly in advance, that scientists would work to isolate what signals they are detecting in an effort to gain the same ability.
That said, there is an IEEE paper which purports to show that electromagnetic disturbances precede earthquakes, and could be used for prediction. I don't have access to anything but the abstract however.
If we determined that some animals are sensitive to impending earthquakes, we'd still have to establish why. It's possible that some animals are sensitive to very low frequency radio waves, and we currently have ELF transmitters (there's one in central Wisconsin) that, if the Navy permitted, could be used for some research. (In the 1990s, we drove into the ELF transmitter, and saw neither a keep-out sign except around some buildings, nor anybody warning us out. I don't know what the post-9/11 security arrangement is.)
There's also the possibility of trace amounts of released gases, or sounds or vibrations, since we know some animals have much more sensitive noses and ears than we do.
It would also help if we could determine if animals are sensitive to no, some, or all impending earthquakes.