Fig. 14

Conceptual diagram of the eruption sequence derived from both deposit data and geophysical analysis (Walsh et al. 2019). Six pulses are recorded by the seismo-acoustic analysis and at least two of those are reasonably energetic (pulses 5 and 6). Pulses 1, 2, 3 and 4 are too weak to deposit ejecta beyond the inner crater (a) and (b). Pulses 5 and 6 are both energetic, and their vents were inclined to the east (c). The inclined explosions generated a coupled ballistic and pyroclastic surge that partially encountered and was contained by the inner crater wall. For the surge component, the crater wall caused significant upflow causing significant atmospheric entrainment and deposition of ash part way up the crater walls. The variable burial of ballistic ejecta and the lack of abundant impact craters suggests that ballistics were falling onto the surge (e) and (f)