How hazardous are tsunamis triggered by small-scale mass-wasting events on volcanic islands? New insights from Madeira – NE Atlantic

Mass-wasting events are a key process in the evolution of volcanic ocean islands. They occur at various dimensional scales and present major source hazard. When collapsed material plunges into sea, destructive tsunamis can be generated. Yet, hazard potential collapse-induced is still poorly understood with different opinions on what consequences to expect from this type events, particularly those related massive island flank collapses. In paper, however, we explore extent triggered by smaller – but more frequent coastal cliff-failures, order isolate critical factors generation, propagation impact these tsunamis. To achieve this, use prime example Madeira, Atlantic Ocean highly vulnerable cliff-failure. Particularly, March 4th, 1930 Cabo Girão event that deadly tsunami. The “Deadly Wave”, as island's inhabitants referred generated tsunami, resulted 19 fatalities. We historical description, morphological analysis, numerical modelling better understand tsunamigenesis tall cliffs failing sea. Interestingly, find relatively small-scale mass-wasting (?0.003 km3 volume) was cause reported tsunami inundated nearest coasts. Our results, fairly agreeing available collapse subsequent descriptions, suggest mainly localized southern coast Madeira Island. Furthermore, our study allows proposing novel morphology-based conceptional model for induced oceanic