One might think that the penchant certain people have – to physically witness infrasound – is uncommon. Yet an experiment conducted in a concert hall in London in 2003 found that 62% of an audience of 750 people reported a variety of reactions to infrasound. Many were physiological: shivers down the spine, a sense of going hot and cold, increased heart rate, headache, an “odd feeling in [the] stomach,” etc. Intriguingly, many of the reports conjured up emotion: feelings of anxiety, panic, excitement, or sorrow. One person volunteered “a sudden memory of emotional loss.”
It’s conceivable that these physical and emotional messages are among the spectrum of what whales and elephants are convey through infrasound. Indeed, many species seem to rely on such avenues for crisis communications. Consider that, over the centuries, a range of creatures – including insects and birds as well as mammals – have been observed to become agitated before natural disasters. The most recent iteration comes from the tsunami that devastated East Asia in 2004. Numerous survivors observed birds suddenly taking flight, elephants trumpeting and fleeing to higher ground, and dolphins moving out to sea. Furthermore, virtually no animal remains were found in the aftermath of the tsunami – in contrast to the roughly 200,000 human bodies. (Check out this video from a PBS Nature program aired in 2008.)
The evidence suggests that various species benefit from an infrasonic or similar ‘early warning’ capacity. Infrasonic waves are produced by many kinds of natural disturbances – volcanoes, earthquakes, tornadoes, avalanches, hurricanes, etc.; the waves’ arrival would precede the disturbance itself and give precious hours or minutes of notice. It’s also possible that animals sense changes in air and water pressure, or that they simply hear the warning signals (a voluminous wave, in the case of a tsunami) far more acutely than humans. Interestingly, while human beings’ ability to detect such cues is relatively paltry, the instruments we deploy may have the necessary sensitivity themselves. Infrasonic waves generated by the 2011 Tohoku earthquake in Japan were picked up by a satellite orbiting 255 km above the earth – high but still at the edge of the earth’s atmosphere.
Another explanation may lie in animals’ sensitivity to electromagnetic field variations. The late Motoji Ikeya, a geophysicist, found that certain animals – especially catfish – react to even minor changes in electromagnetic current. Ikeya developed his theory after noticing, immediately before the earthquake that devastated Kobe, Japan in 1995, that "so many earthworms dug themselves up in my small garden."
Brown, David Jay and Sheldrake, Rupert. “Unusual Animal Behavior Prior to Earthquakes: A Survey in Northwest California.” Animals and Earthquakes. http://animalsandearthquakes.com/survey.htm.