Mount Semeru Erupts Eight Times in Six Hours, Ash Column Reaches 1.2 km
Mount Semeru, which stands 3,676 metres above sea level, was recorded erupting eight times over the past six hours, with eruption heights reaching up to 1.2 kilometres on Friday morning.
The first eruption occurred at 00.24 WIB, though the visual eruption was not observed and was still ongoing when the report was made.
“The second eruption occurred at 01.13 WIB with an observed eruption column height of around 700 metres above the summit,” said Mount Semeru Observation Post officer Liswanto in a written report received in Lumajang.
The third, fourth and fifth eruptions occurred at 01.24 WIB with an eruption height of 600 metres above the summit, followed by eruptions at 04.38 WIB and 04.57 WIB where the visual eruption was not observed.
“Mount Semeru erupted again at 05.15 WIB with an observed eruption column height of around 1.2 kilometres above the summit, or 4,876 metres above sea level,” he said.
According to him, the ash column was observed to be white to grey in colour with moderate intensity moving southwards. When the report was made, the eruption was still ongoing.
Shortly afterwards, another eruption occurred at 05.25 WIB with an observed eruption height of 800 metres above the summit, and the ash column was observed to be white to grey with moderate intensity moving southwards.
The eighth eruption occurred at 05.40 WIB with an observed eruption column height of 700 metres above the summit, and the ash column was white to grey with moderate intensity moving southwards.
“When the report was made, the eruption of Mount Semeru was still ongoing,” said Liswanto.
He explained that volcanic activity at Mount Semeru is currently at Level III (Alert) status, with a recommendation that the public not carry out any activities in the south-eastern sector along Besuk Kobokan as far as 13 kilometres from the summit (eruption centre).
Beyond that distance, the public should not carry out activities within 500 metres of the riverbank along Besuk Kobokan, as there is potential for exposure to expanding hot clouds and lava flows up to 17 kilometres from the summit.
“The public is prohibited from carrying out activities within a five-kilometre radius of the crater/summit of Mount Semeru because it is prone to the danger of ejected incandescent rocks,” he said.
He urged the public to be aware of the potential for hot clouds, lava avalanches and lahars along river flows and valleys that originate 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,” he said.