Two New Islands Emerge Off Anak Krakatau After Month-Long Eruption

A continuous 25-hour eruption of Anak Krakatau in early September generated two offshore mounds, located roughly 760 m to the northwest and 495 m to the southeast of the volcano, according to Indonesia’s Geological Agency. The formations were initially spotted when a drone pilot searching for a missing reporting team inadvertently filmed the northwestern mound, and subsequent reports from mariners and Sentinel satellite imagery verified both features.

The agency has not measured their dimensions or elevation, and satellite data alone cannot confirm if they are fresh vents or accumulations of volcanic debris. Researchers suggest that if they are new vents, volcanic activity may be spreading beyond the central conduit, raising navigation hazards in the Sunda Strait. If they are loose deposits, they could be quickly eroded by waves. This is the first appearance of separate islands within the Krakatoa caldera since Anak Krakatau became a permanent island in 1930.