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About the Project

The Earthsound Project aims to bring the hidden sounds of Earth into conscious awareness.

The gravity of Sun and Moon, the shifting continents, earthquakes, volcanoes, storms, meteors, and ocean waves all contribute to a powerful upwelling stream of acoustic and seismic energy, a chorus of deep sound from below. Usually inaudible, invisible, and impalpable, these restless vibrations ripple across the entire planet, lifting and lowering, flexing and tilting the solid ground, influencing all of us who dwell here on the surface. Invisible subterranean forces unite us all.

The Earthsound Project gathers these deep planetary signals from a worldwide network of sensitive seismometers and microbarometers that are operated by academic research institutions. These signals stream in real time to a cluster of small servers — the Planetary Sound Machine. The Machine accumulates several days of data, which it then converts to audible sound and relays live to listeners around the world via the Internet and broadcast radio.

The Earthsound Project’s sounds can be enjoyed in many ways. Recordings have been used by composers, musicians, dancers, sound artists, and designers of museum exhibitions. Many listeners find joy in simply basking in the ambient sounds of the planet, tuning in to the rhythms of the deep.

In using geophysical technology to create an aesthetic acoustic experience, the Earthsound Project hovers somewhere in the liminal zone between science and art.

Questions & Answers

How does this work?
A global network of sensors — seismic, atmospheric, and oceanic — continuously monitors the planet's geophysical vibrations and provides the raw material for the Project's audio streams. Most of these sensors are operated by academic research observatories around the world. Custom software running on a cluster of cloud-based dedicated computers — the Planetary Sound Machine — continuously gathers data from these sensors via the IRIS consortium in near-real-time, translates them to audible sound, and delivers audified planetary signals to listeners around the world — and, eventually, beyond.
How can I participate?
You can help contribute to heightened planetary self-awareness by sharing and redistributing these sounds in creative ways. Some ideas: set up a public listening kiosk at your school, workplace, or in a nearby park or shopping mall; integrate these sounds into a musical or dance performance; set up a micro-power AM or FM transmitter to broadcast these sounds into your neighborhood, into the atmosphere, or into space. The possibilities are endless. If you need help, just contact me.
Can I edit, copy, paste, remix, tweak, share, and rebroadcast these sounds?
Yes, indeed! The project, its text, and its sounds are governed by a Creative Commons BY-NC license, which means that you can do all those things, provided that: (a) you attribute the source sounds to the Earthsound Project and (b) you don't use them for commercial purposes.
Why can't we usually hear the Earth's sounds?
Most of the Earth's seismic and atmospheric vibrations are simply too low in pitch for us to hear. To make them audible, the Planetary Sound Machine raises their pitch by digitally "speeding them up", in much the same way that playing a vinyl LP record at 78 rpm raises the pitch of the original 33⅓ rpm recording. By speeding up the signals various amounts, we can tune in to different portions of the Earth's acoustic spectrum. Some of the Project's audio streams have been sped up by a factor of 60; others by a factor of several thousand. This is enough to bring many of the Earth's deep sounds into the range of our ears. Each doubling of speed effectively transposes the sounds upward by a musical octave. Some of the sounds in these streams have been transposed upward by more than 11 octaves — much more than the entire range of a concert piano!
What am I listening to?
In the seismic audio streams, the restless whisshhhhh is the planet's natural microseismic background ambience, caused by storm-generated ocean waves interacting with the ocean floor far out at sea. Now and then you may hear the faraway pop! or whoop! of a distant earthquake. And once every week or two you may hear the dramatic boom! of a major earthquake somewhere in the world, as its energy echoes across distant mountain ranges and ocean trenches. If it's a particularly large quake, you'll hear the echoes as its seismic surface waves repeatedly circumnavigate the entire planet.
Sometimes I don't hear much of anything. What's going on?
There are several possible reasons. First, the Planetary Sound Machine automatically adjusts the volume of each audio segment up or down to make room for the loudest signal. This means that when the Earth is relatively quiet, the volume will be turned up high and you'll easily hear the steady background ambient sound of the planet. When a large earthquake occurs near a seismic station, however, the volume will be turned way down and the only sound you might hear is the brief bang! of the earthquake. Second, because many of the sensors are located in remote locations, a hardware or network failure somewhere along the way can result in loss of data for several hours or days. Finally, the software that drives the Planetary Sound Machine is experimental and still under development. I continue to chase down bugs in an effort to make it more resilient to data glitches and other unforeseen conditions.
Can I rely on a steady audio stream for my live dance/music/radio/etc. performance?
Maybe, maybe not. Some audio streams run flawlessly for days or weeks at a time. Others can be flaky and may drop out several times a day. Depending on your project's aesthetic requirements, this unreliability may be a plus, as it hints at the underlying challenge and complexity of listening to the Earth. If your project requires a rock-solid uninterrupted audio program, you might try working with some of the archived recordings that are saved each day. You are welcome to download and use any of those recordings.
What are those purple and blue images?

These are spectrograms that show how the frequencies (pitches) of the sound vary over time. The horizontal axis shows the time, increasing from left to right. The vertical axis shows the frequency of the Earth's vibrations. Brighter (pinker) colors indicate more energy (louder sounds); darker colors (blue) indicate softer sounds. Colors that are smeared over a wide range of times and frequencies correspond to a whooshing or hissing sound. These are the sounds of the Earth's microseismic background, caused by interaction of ocean waves and the Earth's crust. As ocean storms come and go, these sounds rise, fall, and fade away. An earthquake shows up either as a bright spike (a percussive snap! or bang!) over a limited time range, or as a low frequency hook-shaped feature (sounding like a whooop). The latter are the signature of seismic waves traveling long distances across the surface of the Earth.

The white arrows near the top of the spectrograms indicate the time of significant earthquakes around the world. Because seismic waves take some time to travel across the planet, there will often be a time lag between these arrows and their corresponding blips on the spectrograms.

More to come...

Acknowledgments

The Earthsound Project relies on data provided by the following networks and institutions:

(Here is the complete list of FDSN networks.)

Data from these sources are delivered to the Planetary Sound Machine via the IRIS Data Management Center near Seattle, Washington.