Monitoring Volcanic Activity with High Sensitive Infrasound Sensor Using a Piezoresistive Cantilever

In this paper, we propose a high sensitive monitoring method of infrasound evoked by a volcano eruption. The sensor unit is composed of two differential pressure sensors and an air chamber. The pressure resolution of the developed sensor is approximately 0.01 Pa, which is sufficiently small to detect the tiny infrasound. The measurable frequency range is from 0.3 Hz, which is sufficiently low for the infrasound. The sensor units were set at the foot of volcano, Sakurajima, Kagoshima, Japan. It was confirmed that the sensors kept the high sensitive monitoring performance for a month.