Mount Semeru Erupted with Seismic Activity Around 14 Earthquakes

Lumajang: Mount Semeru, located on the border of Lumajang and Malang Regencies, East Java, erupted on Wednesday, June 24, 2026, at 6:22 a.m. Western Indonesian Time (WIB).
 
“An eruption column was observed at a height of around 600 meters above the summit, or 4,276 meters above sea level,” said Mount Semeru Observation Post Officer Yadi Yuliandi, as reported by Antara.
 
The eruption was recorded on a seismograph with a maximum amplitude of 22 mm and a duration of 130 seconds, and was accompanied by a thick, gray ash column that drifted westward.
 
Based on observations conducted from 12:00 a.m. to 6:00 a.m. WIB, Mount Semeru’s seismic activity was dominated by 14 eruption earthquakes with amplitudes ranging from 15 to 22 mm. Three avalanche earthquakes, two explosion earthquakes, one harmonic tremor, and one distant tectonic earthquake were also recorded.
 
Mount Semeru remains at Alert Level III. The public has been advised to avoid the southeastern sector along Besuk Kobokan, within 13 kilometers of the summit.
 
The public has also been advised to maintain a distance of at least 500 meters from the riverbanks along Besuk Kobokan, as the area is prone to pyroclastic flows and lava flows that could reach up to 17 kilometers from the summit.
 
“People are prohibited from entering a five-kilometer radius of Mount Semeru’s crater due to the risk of volcanic bombs,” added Yadi.
 
He has urged the public to stay wary of their surroundings. “Especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat,” Yadi said.
 
(Jonathan Sianto)