Villaggio Globale

Villaggio Globale, mediante un sistema di articoli connessi fra loro e scritti da scienziati, docenti universitari o da divulgatori specializzati, affronta su argomenti monotematici i problemi che preoccupano l’attuale società e stanno mettendo in pericolo la vivibilità delle generazioni future.

Etna - Abstract

Dike propagation energy balance from deformation and seisimic release
Riferimento bibliografico completo: Bonaccorso, A., Y. Aoki, and E. Rivalta (2017), Dike propagation energy balance from deformation modeling and seismic release, Geophys. Res. Lett., 44, doi:10.1002/2017GL074008.

Magma is transported in the crust mainly by dike intrusions. In volcanic areas, dikes can ascend toward the free surface and also move by lateral propagation, eventually feeding flank eruptions.
Understanding dike mechanics is a key to forecasting the expected propagation and associated hazard.
Several studies have been conducted on dike mechanisms and propagation; however, a less in-depth investigated aspect is the relation between measured dike-induced deformation and the seismicity released during its propagation. We individuated a simple equation that can be used as a proxy of the expected mechanical energy released by a propagating dike and is related to its average thickness. For several intrusions around the world (Afar, Japan, and Mount Etna), we correlate such mechanical energy to the seismic moment released by the induced earthquakes. We obtain an empirical law that quantifies the expected seismic energy released before arrest. The proposed approach may be helpful to predict the total seismic moment that will be released by an intrusion and thus to control the energy status during its propagation and the time of dike arrest.