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 1 830 m (6 000 feet) above sea level at 17:30 UTC on October 22, 2025. The advisory was issued by the Darwin VAAC at 17:50 UTC on the same day.

According to the VAAC advisory, ash was reported based on ground observations to flight level 060, which corresponds to approximately 1 830 m (6 000 feet) a.s.l. The ash cloud was moving to the northeast at a speed of approximately 18 km/h (11 mph). Satellite imagery did not confirm the ash due to darkness, and the VAAC stated the height and forecast were based on ground reports and model guidance. The current Aviation Color Code is Orange.

According to the Smithsonian / USGS Weekly Volcanic Activity Report for September 24–30, 2025, the eruption at Ibu continued with dense gray or white-and-gray ash plumes rising 300–700 m above the summit and drifting in multiple directions. Nighttime incandescence was occasionally observed, and the Alert Level remained at 2, with a safety zone of 2 km (1.2 miles) around the crater and 3.5 km (2.2 miles) from the north crater wall opening.

Ibu is a stratovolcano located on Halmahera Island in Indonesia. The volcano is characterized by an active crater that frequently produces ash plumes and lava emissions. Known hazards include ashfall, lava flows, and pyroclastic flows, which can threaten nearby villages within a few kilometers. The area surrounding Ibu is sparsely populated, but several small settlements are present within a 10 km (6.2 miles) radius, increasing the risk during larger eruptive events.