Mount Merapi Intensifies: Authorities Maintain Alert Status Amid Pyroclastic Activity
Mount Merapi, situated on the border of Central Java and the Special Region of Yogyakarta, has entered a period of heightened activity. Over the past three days, the volcano has produced a series of pyroclastic flows, signaling a marked increase in intensity.
According to the Yogyakarta Center for Geological Disaster Research and Technology Development (BPPTKG), the recent sequence of events began on Saturday, May 30, 2026. While initial observations were hampered by dense fog, seismic monitoring recorded a maximum amplitude of 63 millimeters during the first event. Since then, the volcano has erupted at least four times.
Seismic Escalation
The activity intensified further on Sunday night and throughout Monday, June 1, 2026. On Sunday at 10:47 PM local time, a pyroclastic flow reached 1,000 meters toward the southwest, entering the upstream region of the Krasak River. This event was captured by monitoring equipment with a duration of 158 seconds and a maximum amplitude of 25.74 millimeters.
The trend continued into Monday, with two additional eruptions recorded in the afternoon. At 2:09 PM, an eruption reached an amplitude of 64.04 millimeters, followed by another at 3:14 PM with an amplitude of 42 millimeters. Notably, these flows occurred in the absence of rainfall, which typically serves as a trigger for such volcanic activity.
Safety Recommendations
Agus Budi Santoso, Head of BPPTKG Yogyakarta, confirmed on Monday that the volcano’s status remains at Level 3, or “Alert.” Despite the increased frequency of eruptions, there have been no changes to current safety protocols or danger zone delineations.
The established hazard zones remain as follows:
- Southern-Southwestern Sector: A maximum radius of 7 kilometers for the Bedog, Krasak, and Bebeng Rivers, and 5 kilometers for the Boyong River.
- Southeastern Sector: A maximum radius of 3 kilometers for the Woro River and 5 kilometers for the Gendol River.
Looking Ahead
As the situation develops, the continued release of pyroclastic flows indicates that Mount Merapi remains in an active phase. Given the current Level 3 Alert, authorities are likely to maintain strict monitoring of seismic data and visual observations to detect any further escalations. Future developments could include adjustments to the exclusion zones should the intensity of the eruptions change or if the reach of the pyroclastic flows expands beyond the currently identified danger areas.
