Anak Krakatau, the Indonesian island volcano that collapsed in December 2019 triggering a huge tsunami, did produce clear warning signal before the event. That was the assessment of a German-led team which had reviewed all the data.
The scientists say satelites in the months leading up the catastrophe had observed increased temperatures and ground movement on the volcano. Earthquake and infrasound activity was also detected two minutes prior to the collapse of Anak Krakatau’s southwestern flank. When this mass slid into the sea, it sent a wall of water, up to 40m high ground the Sunda strait.
From the passage we understand that...