Seismicity preceding volcanic eruptions: New experimental insights

A variety of seismic signals representing different physical mechanisms precedes volcanic
eruptions. The most meaningful signals are high- and low-frequency earthquakes and volcanic
tremor that have tentatively been related to fracturing and magma transport in the
volcanic edifi ce. We provide experimental support for this association by reproducing magma
migration while recording seismic signals. Opening fractures emit high-frequency acoustic
events, while the switch to low frequency and harmonic tremor accompanies the fl ow of the
melt in the fractures. Discerning between these seismic signals in nature can signifi cantly
refi ne volcanic hazard evaluation.