Using seismic noise to image volcanoes in three dimensions

Piton de la Fournaise, a basaltic volcano located on the Indian Ocean's Reunion island, is one of the most active volcanoes in the world.

Over the last two centuries, eruptions have occurred almost every year. Detailed structural images of volcanic interiors can theoretically be constructed through analysis of earthquake data, but are hampered by irregular distributions of earthquake sources. Brenguier et al. sought to dissect seismic noise retrieved from Piton de la Fournaise, in order to gain understanding about the three- dimensional interior of the volcano. By using surface waves extracted from seismic noise, the authors developed a three- dimensional seismic wave velocity model of the volcano. This model agrees well with previous results and allows the authors to image the shape of the magma conduit system. Further, they performed a preliminary study showing that a few months of seismic noise data will yield similar three-dimensional results to that obtained from a full year's data, suggesting that their method could be applied to other volcanoes in order to improve volcanic hazard assessment.-American Geophysical Union