Volcanic Music

Eruptions Can Give Sound Warnings

THIS ARTICLE tells us that volcanic eruptions can give sound warnings. Villarrica volcano in Chile radiated very low frequency sound waves (infrasound) before erupting in March 2015.

Volcanoes can be compared to musical instruments. They are rather larger but the crater is rather like a horn. Its shape and size determines the sound produced. Lava rising in the crater lake changes the sound produced. 

One of the justifications volcanologists use for their research is that they can forecast eruptions. It seems that they will be adding microphones to their tool kit!

During the few days leading up to Villarrica’s 3 March 2015 explosion, the volcano’s characteristic explosion infrasound changed (top and bottom). Colored disks represent the spatial equivalents of the respective infrasound time series, which were recorded 4 kilometers from the vent; oscillations are mostly absent on 2 March. Waveforms on 27 February had well-defined oscillations that were mostly absent by 2 March (middle). Draped topography was created by the authors from the Shuttle Radar Topography Mission digital elevation model using an image from NASA Earth Observatory. VID and VIC are the stations that recorded the waveform data.