Volcanoes, already rather frightening, are now believed to emit a sound not unlike a scream before they erupt, according to a new study.
A revealed a swarm of smaller tremors that rose in frequency and pitch just before the volcano鈥檚 release. As the quakes become smaller and more numerous, they coalesce into a kind of 鈥渟cream,鈥 that ceases right before the final eruption.
While the source of the tremors isn鈥檛 exactly known, the University of Washington鈥檚 Alicia Hotovec-Ellis, who conducted the study, believes that the harmonic tremors are the result of magma being forced through a narrow conduit deep in the mountain. 鈥淏ecause there鈥檚 less time between each earthquake, there鈥檚 not enough time to build up enough pressure for a bigger one,鈥 she said. 鈥淎fter the frequency glides up to a ridiculously high frequency, it pauses and then it explodes.鈥
The study of the scream, which has also been documented at Arenal Volcano in Costa Rica and Soufri猫re Hills volcano in the Caribbean, should help scientists better model a volcano鈥檚 pressurization patterns, allowing for better understanding of the eruption cycle.
You can hear audio of the volcano鈥檚 siren song .