Volcanoes provide us with various benefits, but can also cause disasters when they erupt. As residents of Japan, a country with many volcanoes, we must understand the dual nature of volcanoes and learn to live with them. At the Institute of Seismology and Volcanology, we conduct research based on geophysical observations to elucidate the mechanisms of volcanic phenomena and develop methods for predicting eruptions. I am engaged in observational research using infrasound and seismic waves. Infrasound refers to a very low-frequency sound wave that is lower than the audible limit to humans (around 20 Hz), and it is generated by volcanic phenomena occurring on the ground surface. By utilizing both infrasound, which propagates through the air, and seismic waves, which propagate through the ground, we can approach phenomena occurring from the Earth's interior to the surface. Field observations are the foundation of our work (Fig. 1). I also conduct laboratory experiments to investigate the mechanisms behind infrasound generation (Fig. 2). Additionally, infrasound is known to accompany various natural phenomena on Earth (such as lightning, fireballs, ocean waves, avalanches, and glacial collapses). I am also involved in observational research on infrasound in Antarctica (Fig. 3).