Abstract by Sarah Shaw
Physics and Astronomy
Directionality of Scale-model Volcano Acoustics
The directionality of the infrasound of volcanoes can be used to estimate the sound power of a volcano and the quantity and ash content of the debri. Often scale-model explosions are used to gain insights into how measured infrasound relates to sound power and directivity. Our goal is to estimate the directionality of these explosions from measurements on an arc not concentric with the origin of the explosion. To learn how to interpret such data, a pretest was conducted using exploding balloons. The balloons were filled with a stoichiometric mixture of oxy acetylene and when exploded produced acoustic shock waves. Balloons were placed in the ground in preformed “craters.” The craters were different shapes to hopefully produce different directionality. Measurements were taken using both circular microphone arrays centered on each of the four crater locations and a single semi-circle array that was not concentric. The goal is to connect the two measurements and determine how to interpret the directionality from data collected from the semicircle setup. This study of acoustic scale-model explosions will help in interpreting volcano infrasound.