Dec 21, 2025: Dramatic Pyroclastic Flows from Merapi Volcano, Indonesia
This video captures a powerful sequence of large pyroclastic flows (awan panas guguran) racing down the southern flank of Mount Merapi, one of the world’s most active and closely monitored volcanoes. Filmed from a remote webcam, the footage shows hot avalanches of ash, gas, and volcanic debris generated by the collapse of lava material near the summit.
Recent Indonesian Government Monitoring Report (Summary)
According to official observations from Indonesian authorities, Merapi has shown intense and sustained activity, including:
Seismic activity recorded:
4 pyroclastic flow earthquakes (APG) with amplitudes of 7–25 mm and durations of 108–188 seconds
82 rockfall (guguran) earthquakes with amplitudes of 1–50 mm and durations of 55–208 seconds
63 hybrid / multi-phase earthquakes with amplitudes of 2–34 mm, S–P times 0.2–0.9 seconds, and durations of 5–61 seconds
6 shallow volcanic earthquakes with amplitudes of 26–78 mm and durations of 7–23 seconds
2 distant tectonic earthquakes with amplitudes of 2–6 mm and durations of 47–75 seconds
Hazard Assessment & Official Recommendations
Authorities report that magma supply is ongoing, meaning further collapses and pyroclastic flows remain possible. Current hazard zones include:
South–Southwest sector:
Lava and pyroclastic flows may impact the Boyong River (up to 5 km) and the Bedog, Krasak, and Bebeng rivers (up to 7 km)
Southeast sector:
Woro River (up to 3 km) and Gendol River (up to 5 km)
Explosive eruptions, if they occur, could eject material within a 3 km radius of the summit
Public safety guidance:
Do not conduct any activities within designated hazard zones
Remain alert for lahars and pyroclastic flows, especially during rainfall
Be prepared for ashfall impacts
Activity levels will be reassessed immediately if significant changes occur
🌋 About Mount Merapi
Located in Central Java, Merapi is infamous for frequent dome growth and collapse, producing deadly pyroclastic flows that travel rapidly down its steep slopes. Continuous monitoring is essential for protecting nearby communities.
⚠️ This video is shared for educational and observational purposes only. Always follow official guidance from local authorities and disaster management agencies.