Volcanic ash from Ibu volcano observed at 1 830 m (6 000 feet) a.s.l., Indonesia

Volcanic ash from Ibu volcano in Indonesia was observed at an altitude of 1 830 m (6 000 feet) above sea level at 23:30 UTC on October 21, 2025. The advisory was issued by the Darwin VAAC at 23:50 UTC on the same day.

According to the advisory, intermittent discrete eruptions were observed through visible satellite imagery. The volcanic ash cloud extended from the surface up to 1 830 m (6 000 feet) and was moving north at 9 km/h (6 mph). The current Aviation Color Code is Orange. Ash height and movement were determined based on ground reports and model guidance.

The most recent Global Volcanism Program summary reported that the eruption at Ibu continued during September 24–30, 2025. Dense gray or white-and-gray ash plumes rose 300–700 m (980–2 300 feet) above the summit and drifted in multiple directions. The Alert Level remained at 2, with the public advised to stay 2 km (1.2 miles) away from the active crater and 3.5 km (2.2 miles) from the northern crater wall opening.

Ibu is a stratovolcano located on Halmahera Island, Indonesia. It frequently produces ash plumes, pyroclastic flows, and lava domes. The main hazards include ashfall affecting local communities and aviation, as well as pyroclastic flows impacting areas within several kilometers. Nearby settlements at risk include local villages on the slopes of the volcano.