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Infrasound, Elephants and Earthquake Detection
mediareport writes "Science News offers a timely antidote to simplistic mumbo-jumbo about the "mythical power" of animal earthquake detection. Anyone intrigued by reports of possible tsunami-avoidance behavior in Sri Lankan wildlife will enjoy this detailed examination of the latest research into low-frequency sound. Elephant rumblings that produce Rayleigh waves are now under serious study for the first time, while others are designing "highly unusual" experiments to test infrasound sensitivity in humans."
Weird (and cool) stuff.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
I wondered about those fishes that died ashore after the tsunami...
The sound wave indeed propagates through water about 1400km/h, much greater than the propagation speed of tsunami wave at this time (~1000km/h). So the fishes most probably have "heard" the low freqency wave. I'm sure no fish can outswim the tsunami, but I'm a tiny bit surprised to see so many of them got stranged in land.
I know the physics of waves, but have little experience in ocean current under sea. Would tsunami wave actually whirl up and down so fast that deep ocean fishes get dredged up fast and get knocked out before dying ashore? Or do they simply get left behind waves and asphyxiate to death?
I'm sure there was lots of infra-whats-a-ma-gig going on, but regardless of those factors, what it comes down to is that animals just aren't as stupid as humans.
When confronted with an unusual, confusing situation, they get the fuck out. Whether it was the vibrations, the noise, or the distant sea swell, doesn't matter, they got the fuck out.
That's loser speak. ;)
What is better for Og: Avoiding the sharp rock that cut him? Or figuring out how to use that sharp rock to cut others?
Avoid fire like the rest of creation? Or use it to keep him warm and build better spears to kill others?
Og thinking that, like all other predators, a healthy, adult mammoth shouldn't be messed with? Or scream and taunt the mammoth to the point where, in order to escape this mad creature, the mammoth tries to flee, forgetting about the large cliff...
Sure, Og's actions lead to a high deathrate amoung Og's kin. But a few Ogs later, the rest of the clan is much better off.
(Warning: non native writer.) Also, most animals can outrun humans. As I understand it, tsunami's can be outrun if you run over 20km per hour. Clearly a lot of big mamals can run faster than that. So that combined with the fact that animals usually do not go investigate how far the sea retracted, makes (bigger) animals byfar more tsunami restistant than humans. I would like to point out however that humans are very successfull multiplying wise. Does anyone know if we outnumber any mamal population (even before we start destroing their habitats)?
-- (:> jms cs.vu.nl (_) --"---
It's possible. Until recently, we didn't know a certain kind of squirrel could communicate in very high frequencies, but alas. But I think the easiest explanation is that the animals could hear the deep rumble of the initial earthquake (inaudible frequencies are created) and decided that something must be up and ran away from the source of the sound.
A blog like any other.
tsunamis do not hit the shore at 500 mph. The reason it's a big wave in the first place is because it slows down.
This is interesting rated but utter nonsense.
A tsunami has not a speed of merely 20km/h but somewhere between 100km/h and 400km/h.
Granted when it approaches teh coast it slows down massively, thats why the waves are that high.
You can play that on your desk by using a sheet of paper. Move it and stop the front edge with your finger while you continue to move it. It waves up.
The animals did not flew the tsunami, they felt the earthquake and moved BEFORE the tsunami came.
angel'o'sphere
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.