AbstractWe explore the capabilities of volcano optoâacoustics, a promising technique for measuring explosion and infrasound resonance phenomena at openâvent volcanoes. Joint visual and infrasound study at Yasur Volcano (Vanuatu) demonstrate that even consumerâgrade cameras are capable of recording infrasound with high fidelity. Passage of infrasonic waves, ranging from as low as 5 Pa to hundreds of Pa, from both explosions and persistent tremor, pressurizes and depressurizes ambient plumes inducing visible vaporization and condensation respectively. Optical tracking of these pressure wavefields can be used to identify spectral characteristics, which vary within Yasur's two deep craters and are distinct for explosion and tremor sources. Wavefield maps can illuminate the propagation of blasts as well as the dynamics of persistent infrasonic tremor associated with standing waves in the craters. We propose that optoâacoustic monitoring is useful for extraction of nearâvent infrasound signal and for tracking volcanic unrest from a remote distance.