Using water cannon experiments to improve understanding of volcanic blasts

The experiment was completed in 2016 and included a setup to measure acoustic signals from human-made blasts which could improve our understanding and early detection of real volcanic eruptions. The upper left image shows a simple plastic soda-pop bottle being filled with super cold liquid nitrogen. The bottle is subsequently sealed with a cap and placed in the ambient water-filled barrel. The difference in temperatures between the bottle and barrel water causes a rapid discharge explosion (lower left image) which is recorded on a pressure sensor near the cannon. Each waveform (right) shows a different eruption experiment. The images were taken from video by Julian Thompson, formerly GNS Science.