Ash emissions from Semeru volcano reach 4.6 km (15 000 feet) a.s.l., Indonesia

On July 8, 2025, intermittent volcanic ash emissions were reported at Semeru volcano, located in Indonesia. The ash emissions were observed reaching an altitude of up to flight level 150, which corresponds to 4.6 km (15 000 feet) above sea level, moving west. The eruption was first reported at 09:19 UTC, with ongoing emissions noted by ground reports and satellite data.

Details from the Darwin VAAC advisory indicate that the current Aviation Color Code is Orange. Satellite imagery could not directly detect the ash cloud due to meteorological cloud cover, but ground observations and model guidance confirmed intermittent discrete ash emissions. The forecast suggested continued ash at similar altitudes drifting west, with updates expected no later than 17:30 UTC on July 8, 2025.

According to the latest Smithsonian/USGS Global Volcanism Program weekly report, activity at Semeru continued from June 25 to July 1, 2025. Multiple daily eruptive events were recorded by the seismic network, often producing ash plumes up to 600 m above the summit. The public was advised to stay at least 3 km away from the summit in all directions due to lahar, avalanche, and pyroclastic flow hazards.

Semeru is a stratovolcano and the highest volcano on Java island, Indonesia. It is known for persistent activity and frequent eruptions, producing hazards such as ashfall, pyroclastic flows, and lahars. The nearest population centers include the town of Lumajang to the east and several rural communities on the slopes, all of which can be at risk during heightened volcanic activity.