The new science of volcanoes harnesses AI, satellites and gas sensors to forecast eruptions

Early in 2018, the volcano Anak Krakatau in Indonesia started falling apart. It was a subtle transformation -- one that nobody noticed at the time. The southern and southwestern flanks of the volcano were slipping towards the ocean at a rate of about 4 millimetres per month, a shift so small that researchers only saw it after the fact as they combed through satellite radar data. By June, though, the mountain began showing obvious signs of unrest. It spewed fiery ash and rocks into the sky in a series of small eruptions. And it was heating up.