Crater-rim collapse at Stromboli volcano: understanding the mechanisms leading from the failure of hot rocks to the development of glowing avalanches

Abstract The failures of volcanic crater-rims frequently lead to the development avalanches glowing rocks, a hybrid phenomenon between rock and pyroclastic density currents, reaching considerable distances from eruptive centres therefore be serious threat for inhabited areas. collapse conditions have been here taken in account by means slope stability analysis using Limit Equilibrium Method on crater-rim Stromboli volcano (Italy). A Stromboli, collapses occurred (at least seven events last two decades) were always associated with high-level magma within conduits, testified increased activity ground-deformation. more frequent/intense produced greater accumulation volcaniclastic material, whereas high level magmastatic thrust deposits. Volcaniclastic material was modelled combining nonlinear failure envelopes as Generalized Hoek Brown criterion, addition failure's envelope rockfill-like described Barton-Kjaernsli taking into consideration presence discontinuities proximal, partially welded, masses. In lithological morphological characteristics crater terrace rim magmatic thrust, effects explosions terms seismic ground acceleration disturbance factor (D) also considered here. While compatible explosive has little influence rims, increase D increases proneness failure.