Volcanic ash from Marapi volcano detected at 3 700 m (12 100 feet) a.s.l., Indonesia

Volcanic ash from Marapi in Indonesia was observed at 3 700 m (12 100 feet) above sea level at 22:30 UTC on October 13, 2025. The advisory was issued by the Darwin VAAC at 22:56 UTC on October 13, 2025.

The observed ash cloud was reported between the surface and flight level 120, which is approximately 3 700 m (12 100 feet). The observation was based on seismogram data and estimated with model guidance, as the ash was not identifiable in recent satellite imagery. The ash was reported moving west at 9 km/h (5 mph). The current Aviation Color Code is Orange. The advisory notes that the volcanic ash is expected to dissipate within 3 to 6 hours.

According to the Smithsonian / USGS Weekly Volcanic Activity Report for September 24-30, 2025, Marapi continued eruptive activity with events recorded on September 24 and 26, though weather conditions prevented visual confirmation. A dense white-and-gray ash plume rose 1 000 m (3 300 feet) above the summit on September 26, drifting east. The Alert Level remained at 2, with a recommendation for the public to remain 3 km (1.9 miles) from the active crater.

Marapi is a stratovolcano located on Sumatra, Indonesia. Known volcanic hazards include ashfall, explosive eruptions, and pyroclastic flows, which can threaten nearby towns and villages such as Bukittinggi, located about 8 km (5 miles) from the volcano. Marapi’s eruptions can cause disruptions to air traffic and impact agriculture and population centers in the surrounding area.