Eruption at Ibu volcano sends ash to 3 685 m (12 100 feet) a.s.l., Indonesia

Volcanic ash from Ibu volcano in Indonesia was observed at 3 685 m (12 100 feet) above sea level at 07:30 UTC on October 9, 2025. The advisory was issued by the Darwin VAAC at 07:50 UTC.

Ash was reported between the surface and flight level 120 (approximately 3 685 m or 12 100 feet) and was moving northeast at 9 km per hour (5.6 mph). The observation was supported by Himawari-9 satellite and ground reports, although ash was currently obscured by meteorological clouds and is expected to dissipate within six hours. The height and movement of the ash are based on model guidance and ground observations. The current Aviation Color Code is Orange.

According to the latest Smithsonian / USGS Weekly Volcanic Activity Report, eruptive activity 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, drifting in multiple directions. Nighttime incandescence at the summit was noted on several occasions. The Alert Level remained at 2, advising the public to stay 2 km (1.2 miles) away from the active crater and 3.5 km (2.2 miles) from the north crater wall opening.

Ibu is a stratovolcano located on Halmahera Island in Indonesia. It is characterized by a broad summit crater with ongoing explosive activity over recent years. Hazards at Ibu include ashfall, pyroclastic flows, and potential lava flows. The nearest populated communities are within 10 km (6.2 miles) of the volcano, and local populations are periodically impacted by ashfall events.