Earth sounds

Posted: Tue Dec 19, 2006 7:09 pm

Okay this one's a bit off the beaten path, but I'll share it anyway. A friend of mine sent me this link of acoustic translations of seismic phenomena (earthquakes). Kind of funky, you might need to either be a geologist or like didjeridoo music to see the appeal. There are a few other recordings on the base web site addy.

http://www.jtbullitt.com/earth/dome/clips/breathe.mp3

Damiatrix Joined: 21 Aug 2006 Posts: 589

That's really neat. So what does it mean "acoustic translations?" Are those actual earth sounds or instruments? Because if they're not instruments, I find it wonderful that the earth creates its own drumming Smile

. Really good stuff hon. I like it when things are "off the beaten track."~~Maia

Posted: Wed Dec 20, 2006 7:53 am

Actual earth sounds. What this guy is doing is 'art'. He's taking seismograms -- measurements of the earth's vibration -- and making an immersive environment. This is the sound component. In its simplest case, all a seismograph really is is a pen hanging on a spring...earth moves, pen writes a squiggle. The seismograms are available for free from various governmental agencies including the USGS (your tax dollar at work - maybe money well spent, lol). He does some signal processing to convert the analog signal to digital, and then he cranks up the speed it enough so we can hear it. There has been some conjecture that dogs, elephants and such can hear these low frequency tones.

His description of the clip:

In this clip, we hear a swarm of Indonesian earthquakes as recorded in Riyadh, Saudi Arabia (left channel) and Tennant Creek, Australia (right). Many of these quakes are large enough to set the planet "ringing" in its natural modes of vibration. One the most fundamental of these modes is the so-called "breathing" mode (0S0), in which the entire planet expands and contracts rhythmically once about every 20 minutes. I've accelerated this recording to bring this "breathing" mode in synch with the average human respiration rate (once every 5 seconds). While you listen, your breath rises and falls along with the rising and falling of the Earth itself.

I should note that in all of these recordings, that delicious reverberation is entirely natural; I have not added any reverb or echo. That spacious quality comes from the vast spaces inside the Earth itself.
—Time-acceleration = ×245 (1 second = ~4 minutes Earth time; this 2-minute recording captures about 8 hours of real Earth time).

(Avan's note. The reverberation results from a combination of 'echoes' off rock layers in the earth, and the fact that there were 2 different recording points. You hear both a real echo and a 'beat', like you hear when you pluck 2 closely but not exactly tuned strings)

Damiatrix Joined: 21 Aug 2006 Posts: 589

WOW Tim,

That's intriguing stuff. I would love to hear more..of course, I'd love to hear a full out earthquake or the wooshing of a tsunami. We might find it deadly, but I imagine that the earth just happened to have a a series of hiccups LOL. And the heartbeating...I don't think that I am able to wrap my head around what you have shown us to give it it's true importance. I'm only grasping the fringes and I think its awesome.~~Maia