Mount Semeru on the border of Lumajang and Malang, East Java, erupted on Thursday night, January 1, 2026, with an eruption column reaching 900 meters above the peak. This marks the fourth eruption of the day, following three in the morning. The Center for Volcanology and Geological Hazard Mitigation (PVMBG) maintains alert status and issues safety recommendations for nearby residents.
Mount Semeru, Java's highest volcano, showed renewed activity on January 1, 2026. According to Semeru Observation Post officer Sigit Rian Alfian, the eruption occurred at 18:37 WIB with an eruption column height of about 900 meters above the peak, or 4,576 meters above sea level. "An eruption of Mount Semeru occurred on Thursday at 18:37 WIB with the observed eruption column height around 900 meters above the peak or 4,576 meters above sea level (mdpl)," he stated in a written report.
The ash column was observed as white to gray with thick intensity drifting toward the northeast and east. The eruption was recorded on the seismograph with a maximum amplitude of 23 mm and a duration of 153 seconds. Earlier that morning, the mountain erupted three times: at 01:26 WIB reaching 1,000 meters, at 04:01 WIB 900 meters, and at 05:29 WIB 900 meters.
Currently, Mount Semeru is at Level III or Alert status. PVMBG recommends that the public avoid activities in the southeast sector along Besuk Kobokan up to 13 km from the peak. Beyond that distance, stay 500 meters from riverbanks due to potential hot cloud expansion and lahars up to 17 km. Additionally, activities are prohibited within a 5 km radius of the crater due to the risk of projectile rocks.
Residents are advised to be vigilant against hot clouds, lava avalanches, and lahars in rivers such as Besuk Kobokan, Besuk Bang, Besuk Kembar, Besuk Sat, and tributaries of Kobokan. These recommendations aim to protect communities from the recurring eruption hazards.
