Mount Semeru Erupts Five Times This Morning
Mount Semeru, situated on the border of Lumajang and Malang regencies in East Java, experienced five eruptions on Monday morning, with the height of the ash columns ranging from 300 to 700 metres above the summit.
The first eruption occurred at 00:18 Western Indonesia Time, with an observed ash column height of approximately 500 metres above the peak. The ash column was observed to be white to grey with moderate intensity, drifting northwards.
“It then erupted again at 00:31 Western Indonesia Time, with an observed ash column height of around 700 metres above the summit,” said Mount Semeru Observation Post Officer Liswanto in a written report received in Lumajang.
He explained that the third eruption occurred at 01:46 Western Indonesia Time, with an observed ash column height of about 600 metres above the peak. The ash column was white to grey with moderate intensity, moving northwards.
The highest mountain on Java Island erupted once more at 05:50 Western Indonesia Time, with an observed ash column height of roughly 300 metres above the summit. The white to grey ash column, of moderate intensity, drifted towards the southwest.
At 07:56 Western Indonesia Time, Mount Semeru erupted again, producing an ash column observed to be approximately 700 metres above the peak. The thick, white to grey ash column drifted southeastwards. This eruption was recorded on a seismograph with a maximum amplitude of 22 millimetres and a duration of 120 seconds.
Liswanto explained that the volcanic activity of Mount Semeru is currently at Status Level III (Alert), with a recommendation that the public refrain from any activities in the southeastern sector along Besuk Kobokan, up to 13 kilometres from the summit (the eruption centre).
Beyond that distance, the public is advised not to conduct activities within 500 metres of the riverbank along Besuk Kobokan, due to the potential for hot cloud expansion and lava flows reaching up to 17 kilometres from the peak.
“The public is prohibited from conducting activities within a five-kilometre radius of the crater or summit of Mount Semeru, as it is prone to the danger of incandescent rock projectiles,” he stated.
He urged the public to remain vigilant against the potential for hot clouds, lava avalanches, and lahars along the river channels and valleys originating at the summit of Mount Semeru.
“Especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahars in small rivers that are tributaries of Besuk Kobokan,” Liswanto added.