“…During basaltic volcanic eruptions, common types of bombs have included ballistically ejected varieties, including 'breadcrust' bombs, as well as rounded features that form with ballistic ejection, such as accretionary balls (also known as lava balls), that form through addition of mass to their outer portions during rolling within lava ows. Ballistic volcanic bombs have been of particular interest for both understanding volcanic processes to examine their in-ight dynamics 4,5,9 , the mechanisms of magma fragmentation 10 , as well as the dangers that they present for the destruction of manmade structures, and the preservation of life [11][12][13] , and they are a key aspect when considering the growing consensus that lower magnitude eruptions, such as that at La Palma, can cause signi cant local, regional and global damage and potential disasters 14 .…”