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From Webster’s Revised Unabridged Dictionary (1913):

Earthquake \Earth”quake`\, n.

A shaking, trembling, or concussion of the earth, due to subterranean causes, often accompanied by a rumbling noise. The wave of shock sometimes traverses half a hemisphere, destroying cities and many thousand lives; — called also {earthdin}, {earthquave}, and {earthshock}.

NOT from Webster’s Revised Unabridged Dictionary (c. 2007):

Soundquake \Sound”quake`\, n.

A nonsensicial term usually referring to the sonification of a digitally recorded seismogram, where normally subsonic seismic energy is mapped to the human audible range. The mapping is typically accomplished by time compressing or pitch shifting the original seismic data.

The short scoop on this Web site

  • All seismic data are from the IRIS Data Management Center . The earthquake hypocenters are from the NEIC
  • The different seismic stations are part of the GSN network. Each station has a three-component, broadband seismometer recording at either 20 Hz or 40 Hz.
  • For each earthquake/station pair, we time compress ~20+ minutes of earthquake signal into a few seconds. This makes the earthquake signals audible.
  • As a result of time compression, a 1-Hz P-wave plays back at ~550 Hz.
  • The audio files are in stereo–sort of. The right/left stereo components are mixed from the horizontal and vertical seismometer channels.
  • The maximum amplitude of all seismograms has been normalized to 1. For station records without a large amplitude P or S wave, this means that the noise can be quite loud.
  • Each movie is labeled with the station code, geo-coordinates, distance from the earthquake, as well as back-azimuth. Predicted-arrival times of the P-wave, S-wave, and surface wave (L) are marked.
  • The accuracy of the above statements is subject to change.
  • There’s no real point to this Web site. We just get a kick out of listening to seismograms.
  • Sound conversion, movie making, and posting of the earthquake data is done automagically and sometimes things don’t work right.

FAQ

Why can’t I hear anything?

1. Maybe you forgot to turn up the volume.

2. Maybe your speakers lack a ┬álow frequency response (important for hearing large earthquakes–require a good subwoofer).

3. Maybe the earthquake is small and too far away from the seismic station to produce a good soundquake.

4. Maybe the earthquake is large (M > 7) and our simple audification ┬áprocedure failed ┬áto make the dominate energy audible–sorry.

5. Maybe our soundquake bot screwed up and there’s nothing there to hear–it happens.
Who’s responsible for this?
This site is developed and maintained by Aaron Ferris and Josh Stachnik… sonifications at gmail dot com

An incomplete list of useful software used to generate this site