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April 21, 2006 — In any given instant, one or more rocky plates beneath Earth's surface are in motion, and now visitors to a California museum exhibit can hear virtually every big and small earthquake simultaneously in just a few seconds off real time.
Scientists have captured earthquake noises before, but this is believed to be the first instantaneous, unified recording of multiple global tectonic events, and it sounds like the constant, dull roar of the world's biggest earthquake chorus.
"There can't be silence," said Franz John, who created the museum project with sound artist Ed Osborn and colleagues. "If you 'heard' silence, the Internet connection would have broken down, or the planet would be dead."
The project, called "Turing Tables," was inspired by mathematician Alan Turing, whose theory held that individuals could create something infinite out of a potentially finite source.
Turing focused on infinite number chains, but John's interest is in the "tectonic forces and energies of a matrix, which is visibly and continually updating and renewing itself."
Sascha Brossmann, who was the project's computer programmer, explained to Discovery News how Turing Tables works. First, a computer program taps into the United States Geological Survey's database that gathers plate movements from all regions of the world.
Since this database does not include smaller international events, it is supplemented with data from a number of regional geographical institutes.
Information about earthquakes, no matter how large or small, includes such data as time, duration, location and magnitude. A variety of monitoring techniques, such as seismographs, is used around the world to collect this data. An independent computer program designed by the exhibit team then gathers all of this information.
John said that to create the installation, "We use a sensorium of digital instruments that are triggered directly by the tectonic data."
The instruments electronically match sounds, images and even vibrations to the rhythm and intensity of Earth's movements.
Since the geological databases are on the Internet, which doesn't always operate in precise real time, listeners hear events that occurred only a few seconds beforehand.
John and his colleagues hope the exhibit will instill an "archaic feeling" and a "consciousness that the earth is an organism, that it moves and that it can be understood as an organism in constant flux."
Peter Westbroek, professor emeritus of geobiology from the University of Leiden in the Netherlands, is writing a book on the science of complexity and its role in society.
Westbroek told Discovery News that experiencing "Turing Tables" feels "as if one is located in the middle of the earth and hears how plate tectonics keeps the planet in constant motion, cracking and crunching.
"We sense the destructive power of these giant forces as they produce volcanic eruptions, earthquakes and tsunamis, but realize at the same time that without these rumblings, the earth would be a dead place, as plate tectonics turns the planet inside out, ensuring a constant supply of mineral foodstuff at the planetary surface."
He added, "To realize that this motion has been going on at the planetary scale for billions of years is a dazzling experience, which helps us to get close to the planet we inhabit."
"Turing Tables" opened at the The Exploratorium science museum in San Francisco on March 31.