Two new islands spotted around Anak Krakatau after major September eruption

Two new islands have emerged in the waters surrounding Mount Anak Krakatau following last month’s major eruption that grounded flights for days, the head of Indonesia’s volcano monitoring agency said on Friday.

The formations were spotted in Sentinel satellite imagery of the water-filled caldera in which Anak Krakatau stands, Rita Susilawati of the PVMBG Centre for Volcanology and Geological Hazard Mitigation told AFP.

The islands sit in the Sunda Strait between Java and Sumatra: one about 760 metres northwest of the volcano, the other roughly 495 metres southwest. Rita said it was too early to call them Anak Krakatau’s “children” — the volcano itself emerged from an underwater eruption after the massive 1883 Krakatau blowout, and “anak” means child in Bahasa Indonesia.

It is not yet clear whether they are rising from the caldera’s base as Anak Krakatau did, or are merely deposits of volcanic material. Several landmasses briefly emerged from 1927 only to erode away before an enduring island formed in 1930 — and the new pair may similarly be eroded away over time.

Anak Krakatau erupted for 25 hours non-stop in September, blanketing cities in ash and stranding more than 300,000 passengers after airport closures. It remains at alert Level 2 — the second-lowest of four — with a three-kilometre (1.86-mile) exclusion zone. Five journalists covering the eruption were declared presumed dead with three boat crew nearly two weeks after their vessel disappeared. Indonesia sits on the Pacific Ring of Fire, where colliding plates drive intense volcanic and seismic activity.