The volcanic activity of Mount Merapi, located on the border between the Special Region of Yogyakarta and Central Java, has shown high dynamics once again. The Geological Disaster Technology Research and Development Center (BPPTKG) reported eight incandescent lava avalanches flowing toward the southwest sector, with a maximum travel distance of 1,800 meters during observations on Tuesday (21/7/2026).
According to a report from MAGMA Indonesia, the eruptive material was observed flowing into the Krasak and Sat or Putih river channels. Visually, thin white crater smoke was seen rising up to 25 meters above the summit. Although the weather around the mountain was clear, indicators suggest that the magma supply within Merapi remains ongoing continuously.
In addition to surface avalanches, seismic records also confirm the volcano's high intrinsic activity. Over a six-hour observation period, 17 avalanche earthquakes, 22 multi-phase (hybrid) earthquakes, 6 shallow volcanic earthquakes, and 1 distant tectonic earthquake were recorded. The high intensity of these earthquakes increases the potential for pyroclastic flows in disaster-prone areas.
To date, Mount Merapi's activity level remains set at Level III (Alert). The Center for Volcanology and Geological Hazard Mitigation (PVMBG) urges the public to clear all activities from the recommended danger zone, which includes river channels in the south-southwest sector up to a 7 km radius and the southeast sector up to 5 km. Residents are also reminded to stay vigilant regarding cold lahar hazards when rain falls on the summit area.
