Direct measurements (9): Acoustic records
Yasur, 1994
Microphone,
Yasur, 1994
Sound is produced by a
volcano has a strong intensity
Sound : variation of pressure,
which propagate in a compressible fluid
correspond to density variations
in an elastic media
radiation of sound in air from
volcano vent
Sound waves are longitudinal waves
(P):
elements of fluid move parrallel to
the direction of propagation
move back and forth: zones of
compression and dilatation
Acoustic: related to oscillatory motion
identical to seismology except propagation in air