Gary D. Hoffmann

Island arc debris avalanches and tsunami generation

On the early morning of 13 March 1888, roughly five cubic kilometers of the Ritter Island volcano fell violently into the sea northeast of Papua New Guinea (Figure 1). This event, the largest lateral collapse of a volcanic island in historical time, flung devastating tsunamis tens of meters high onto adjacent shores [Cooke, 1981]. Calamitous as they might be, natural disasters like these must be viewed in perspective. One should ask, “Were the events of that March day unique, or are they common geological occurrences?” Partly to address this question, a seafloor imaging and sampling program was conducted around Ritter Island and elsewhere along the Bismarck volcanic arc during November–December 2004 on the research vessel Kilo Moana.