Mount Semeru erupts with pyroclastic flow

Mount Semeru, on the border of Lumajang and Malang regencies in East Java, erupted accompanied by a pyroclastic flow on Tuesday evening.

“An eruption of Mount Semeru occurred at 20.33 WIB, but the height of the eruption column could not be observed because it was obscured by fog,” said Mount Semeru Observation Post officer Mukdas Sofian in a written report received in Lumajang.

According to him, the eruption of the mountain, which stands 3,676 metres above sea level, was recorded on a seismogram with a maximum amplitude of 22 mm and a duration of approximately 3 minutes 55 seconds.

“The eruption of Mount Semeru was accompanied by a pyroclastic flow with an unknown runout distance because the visual of the mountain was obscured by fog,” he said.

He explained that volcanic activity at Mount Semeru is currently at Level III, or Siaga status, with a recommendation that the public not carry out any activities in the southeastern sector along Besuk Kobokan as far as 13 km from the summit (eruption centre).

“Beyond that distance, the public must also not carry out activities within 500 metres of the riverbank along Besuk Kobokan because of the potential to be affected by the expansion of hot clouds and lava flows up to 17 km from the summit,” he said.

The public is also prohibited from carrying out activities within a 5 km radius of the crater/summit of Mount Semeru because of the danger of incandescent rock projectiles.

The public was also asked to be aware of the potential for hot clouds, lava avalanches, and lahars along river flows 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,” said Mukdas Sofian.