On 22 Dec 2018, continued eruptions of Anak Krakatau had accumulated too much weight on the cone, which is built on top of a steep underwater slope. This made it prone to landslides and explosions like this one could have triggered it to give way. (Photo: Tom Pfeiffer)
Participant on our Krakatau Volcano Special tour
managed to capture this extraordinary explosion, which involved a small lateral blast, by video. The video has gone viral since it was first published. It shows a place that now no longer exists: two months later, the cone collapsed into the sea and caused a deadly tsunami that hit Java's west coast. An event like this might well have been a final trigger for this to happen.