2020 Volume 34 Issue 4 Article ID: 2020.T015
We observe sounds associated with continuous bubbling in fluid in daily lives. We call them ‘Buku-buku’ sounds. Because similar processes occur at active volcanoes, ‘Buku-buku’ phenomena provide good Kitchen Earth Science subjects. This study investigated bubble sounds using hair-gel solutions with two viscosities. Various waveforms were observed in the air and in the liquid. We focused on two types of airwaves. The one was observed with the relatively low-viscosity fluid and generated by bubble oscillation on the surface. The other was observed with the higher viscosity and generated by bubble opening at the surface. Both types of waves showed frequency gliding from low to high, for which we proposed models. Scaling issues and implications for volcano acoustics are discussed.
