When Earthquakes Sing

Earthquakes are caused by powerful movements of tectonic plates, and like all movements where two objects collide or physically interact, sound is also produced. If you happen to experience an earthquake first-hand, you’re unlikely to be hanging around to analyse what it sounds like; fortunately, researchers have done the hard work for you…

Time-Stretching Seismic Events

Due to the massive size of the bodies involved, the sound of an earthquake typically registers in the range below 1Hz. However, by compressing the time-axis of an earthquake’s audio, one can bring it into the range of human hearing so that visual analysis can be accompanied by an auditory analysis.

This is exactly what researchers at Berne University of the Arts in Switzerland have done. You can see charts of seismic events accompanied by time-stretched recordings here.

The Great Data Shakedown

How humans interpret information is greatly influenced by the methods used to present that information. This is true of general human interaction as well as statistics; even when the underlying message remains the same, how we express it can fundamentally alter how the recipient responds. Of course, in human interaction, a vast array of ‘meta-data’ communicated via tone and body language can subtly add nuances to the message.

When interpreting data scientifically, it can be very useful to look at the same information in different ways. This may allow you to see trends that were not apparent in previous views, and form a more comprehensive analysis of the situation. Florian Dombois makes this comparision between graphical and auditory presentation of seismic events:

the eye is good for recognizing structure, surface and steadiness, whereas the ear is good for recognizing time, continuum, remembrance and expectation. In studying aspects like tectonic structure, surface deformation and regional seismic risk the visual modes of depiction are hard to surpass. But in questions of timely development, of characterization of a fault’s continuum and of tension between past and expected events the acoustic mode of representation seems to be very suitable.

Although not related to audio seismology, this TED talk from Hans Rosling is an interesting demonstration of how statistics can be presented in revealing ways.