On 22-26 September 2018 there was a rare opportunity to see an eruption from the Indonesian volcano Krakatoa under clear skies.
By HansPeter Roesli (Switzerland)
It is difficult to get clear views from space of erupting Indonesian volcanoes. But in late September the eruption from the volcano Krakatoa (Krakatau) offered such an occasion, as documented by a sequence of Volcanic Ash RGBs from Himawari-8 on 22–26 September (Figure 2).
Figure 2: Himawari-8 Volcanic Ash RGB animation, 22 Sept 04:00 UTC–26 Sept 05:00 UTC. Download animation (MP4, 19 MB).
The Global Volcanism Program of the Smithsonian Institution reported: “Based on satellite data, wind model data, and notices from PVMBG, the Darwin VAAC reported that during 18-24 September ash plumes from Anak Krakatau rose to altitudes of 0.9–3.7 km (3,000–12,000 ft) a.s.l. and drifted in multiple directions. The Alert Level remained at 2 (on a scale of 1–4); residents and visitors were warned not to approach the volcano within 2 km of the crater. “
The animation in Figure 2 shows that skies were mostly clear, in particular on 24 September, where the dark-magenta coloured, long ash plume was most prominent. On 22 September, between 09:20 UTC and 10:30 UTC, an SO2 plume was also very visible, e.g. at 10:10 UTC the green plume to the right of the red arrow on Figure 1 (top right, click to expand).
Activity at Krakatau (NASA Earth Observatory)