Imagine that you are a scientist working in Antarctica.
You've suffered from freezing temperatures, drilled ice cores to learn more about our planet, and of course tossed some ice down a really deep hole to hear him 'drink'.
Yes, this is the kind of pastime that people are busy living in some of the most inhospitable corners of our planet.
Thanks to geochemist John Andrew Higgins on Twitter, you too can experience this strange joy as researchers have recorded fantastic sounds made by a block of ice falling into a 137-meter well.
What does a 9 inch ice core sound like when dropped down a 450 foot hole? Like this! Credit to @peter_neff for the idea and @Scripps_Polar, @sciencejenna, @GeosciencesPU, @US_IceDrilling, and @paleosurface for the execution! pic.twitter.com/pW7LxKdbUB
– John Andrew Higgins (@blueicehiggins) February 7, 2020
Why the hell is this strange sound?
We have an answer to this, thanks to Peter Neff, a glaciologist who may have started the tradition of throwing ice into very deep holes and recording the result.
Back in 2018, Neff, like a piece of ice, falls into a 90-meter well, and this video went viral – it gained 10 million views on Twitter alone.
https://twitter.com/peter_neff/status/968911225919700992?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E968911225919700992&ref_url=https%3A%2F%2Fwww.sciencealert.com%2Fhere-s-why-ice-falling-down-a-450-foot-hole-makes-this-super-weird-noise
There are two factors at play, Neff said – the Doppler effect and how sound waves travel throughout the well.
“The first thing you hear when ice falls is a change in sound,” Neff explains in the accompanying video.
“This is the Doppler effect.”
You've probably experienced the Doppler effect many times – this is the reason a car sounds different when it approaches you and then moves away. This small illustration below shows how sound waves from a moving source change in frequency (and therefore in height) as they travel.
(Charly Whiskey / Wikimedia / CC BY 3.0)
However, when it comes to ice, in addition to the Doppler effect, sound waves from falling material also have difficulty exiting the hole.
“Then, when the ice hits the bottom of the borehole, the sound not only goes straight – the sound waves begin to bounce off the borehole walls,” Neff explains.
'That's why you hear it' Pew! 'with some kind of heartbeat sound.'
Sources: Photo: (@ blueicehiggins / Twitter)
