New islands appear in Sunda Strait after Anak Krakatau eruption

Two new islands have emerged in the waters surrounding Mount Anak Krakatau following a major eruption in September 2026, according to the Head of Indonesia's Volcano Monitoring Agency. Rita Susilawati of the PVMBG Centre for Volcanology and Geological Hazard Mitigation told AFP that the formations were identified via Sentinel satellite imagery within the water-filled caldera. One island is located approximately 760 metres northwest of the volcano, while the second sits 495 metres to the southwest. Sentinel is an Earth observation fleet developed by the European Space Agency.

The emergence follows a 25-hour non-stop eruption that blanketed cities in ash and forced a two-day closure of multiple airports, including those serving Jakarta. The disruption left more than 300,000 passengers stranded before flights resumed. While "Anak" means child in Bahasa Indonesia, Ms. Rita stated it is too early to officially name these formations "children" of the volcano. Further research is required to determine if they are emerging from the caldera base or are composed of volcanic material deposits.

Historical data from the PVMBG indicates that several landmasses briefly appeared in the caldera starting in 1927 before eroding. An enduring island eventually formed in 1930, creating the current Anak Krakatau. The volcano itself was created by an underwater eruption in the depression left by the massive 1883 blowout of the original Krakatau. Experts warn that these two new formations may similarly disappear due to erosion over time. Currently, Anak Krakatau remains at alert Level 2, the second lowest of four danger categories.

Safety remains a primary concern as authorities advise people to stay at least three kilometres away from the eruption centre. The September eruption proved fatal for five journalists and three boat crew members who were declared presumed dead after their vessel disappeared nearly two weeks into their mission. Indonesia continues to face high seismic activity due to its position on the Pacific Ring of Fire, where the meeting of continental plates frequently triggers volcanic events.

What to watch: Results of geological research to determine if the islands are permanent landmasses.

Editor's note: Thoroughly incorporates numbers, context, and background from the detailed source text.