The unexpected explosive sub-Plinian eruption of Calbuco volcano (22–23 April 2015; southern Chile): Triggering mechanism implications

Fabio Arzilli, Daniele Morgavi, Maurizio Petrelli, Margherita Polacci, Mike Burton, Danilo Di Genova, Laura Spina, Giuseppe La Spina, Margaret E. Hartley, Jorge E. Romero, Jonathan Fellowes, Juan Diaz-alvarado, Diego Perugini