Mount Semeru, located in Lumajang Regency, East Java, showed significant volcanic activity again on Monday (29/6/2026) afternoon. According to a report from the Semeru Volcano Observatory (PPGA), the eruption occurred at 16:39 WIB, spewing an ash column 1,200 meters above the peak of the Jonggring Saloko crater.
PPGA officer Sigit Rian Alfian noted that the eruption was recorded by a seismograph with a maximum amplitude of 22 millimeters and lasted for 129 seconds. In addition to the ash column, field observers also reported a moderate booming sound accompanying the volcanic activity.
The Head of the Lumajang Regional Disaster Management Agency (BPBD), Isnugroho, stated that there have been no reports of damage or casualties resulting from the eruption so far. Community activities on the slopes of the mountain are reportedly continuing as usual, and there has been no instruction to evacuate.
Although conditions are considered conducive, the BPBD remains vigilant about the potential for ashfall, which is predicted to affect the Pasrujambe District due to the wind blowing eastward. Given that Mount Semeru's status remains at Level III (Alert), the public is urged to remain highly vigilant.
Authorities strongly advise the public not to conduct any activities in the southeastern sector along Besuk Kobokan within a 13-kilometer radius from the peak. Additionally, residents are prohibited from activities within 500 meters of the riverbanks along the Besuk Kobokan flow to prevent threats from hot clouds, lava flows, and cold lahar mudflows, especially if heavy rain occurs around the summit.
