Hydroacoustic observations of volcanic degassing

Hydroacoustics is an often overlooked tool for volcanic monitoring, capable of recording everything from the release of millimetre sized bubbles to small scale phreatic eruptions and gas blowouts. Over the last 4 years we have deployed hydrophones in a range of subaqueous volcanic environments, from oceans to crater lakes, at depths from 1 to 350 m. Here we report on these experiments, describe our observations and present the recordings for use by the wider scientific community.