On active explosive volcanoes, volumetric sources rapidly expanding in the atmosphere produce infrasound providing valuable insights into eruption dynamics and into the state of volcanic activity in general.
On volcanoes characterized by dome growth, infrasound can be generated by non-explosive sources related to dome collapses, and pyroclastic flows. Large domes and kilometers-high explosive columns can collapse generating large and devastating pyroclastic density currents. The ability to detect volcanic explosions and track pyroclastic flows in a timely fashion is crucial to volcano monitoring operations and can positively impact risk management in Montserrat as well on other volcanoes characterized by similar activity. In order to improve the capabilities to monitor hazardous explosions and pyroclastic flows, a permanent small-aperture infrasonic array has been installed on Montserrat within the framework of a collaborative effort between MVO and the Dipartimento di Scienze della Terra (DST), University of Florence, Italy. The infrasonic array is installed at a distance of about 3000 m from the active summit lava dome on SHV, at the St. George's Hill site (Figure 2a). The array has an aperture of 200 m and a "star" geometry of 3 satellite sensors located at 100 m from a central station. The array is able to detect explosive events and track pyroclastic flows in real-time, thus, improving the efficiency of the response of the Montserrat Volcano Observatory (MVO) during eruption crises.