Lumajang. On the first day of 2025, Mount Semeru exhibited heightened activity with 10 eruptions recorded by officers from the Mount Semeru Observation Post between 01:12 a.m. and 6:27 p.m.

The most recent eruption, though not visually observable, was captured on the seismograph with a maximum amplitude of 22 mm and a duration of 129 seconds, according to Mukdas Sofian, an official from the observation post in Lumajang Regency, East Java.

The strongest eruption occurred at 5:20 a.m., producing a visible column of volcanic ash and smoke that reached approximately 500 meters above the summit.

Mount Semeru remains under an alert status, which has been in place for the past week. The Volcanology and Geological Disaster Mitigation Center (PVMBG) has prohibited activities within an 8-kilometer radius southeast of the summit, particularly along the Besuk Kobokan area.

Beyond this zone, residents are advised to maintain a safe distance of at least 500 meters from riverbanks due to the potential risk of expanding hot clouds and lava flows.

“People are also prohibited from engaging in activities within a 3-kilometer radius of Mount Semeru’s crater due to the risk of hot rock eruptions,” Mukdas warned.

The public is urged to remain vigilant for potential hazards, including hot clouds, lava flows, and rain-triggered mudslides along rivers and valleys originating from the summit, such as Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat.

At 3,676 meters, Mount Semeru is the tallest mountain on Java Island and a popular destination for hikers and mountaineers. However, the Bromo Tengger Semeru National Park Authority has temporarily closed Mount Semeru's hiking trails from January 2 to 16, citing anticipated extreme weather conditions at the start of the year.

In December 2021, Mount Semeru’s eruptions caused significant devastation, claiming at least 22 lives and injuring dozens more. Lava flows and thick columns of hot ash buried several villages on its slopes, while torrential rains mixed with volcanic ash triggered a flood of hot mud, destroying homes and vehicles.