Mount Semeru erupts with ash column 800 metres above summit

The volcanic ash column of Mount Semeru was observed to be white to grey in colour with moderate intensity, drifting towards the southwest.

Mount Semeru, located on the border of Lumajang and Malang regencies in East Java, erupted on Friday morning with an eruption height reaching 800 metres above the summit.

“Mount Semeru erupted at 06.20 WIB with the observed eruption column height around 800 metres above the summit, or 4,476 metres above sea level,” said Mount Semeru Observation Post officer Liswanto in a written report received in Lumajang.

According to him, the volcanic ash column was observed to be white to grey in colour with moderate intensity, moving towards the southwest.

“At the time the report was made, the eruption of the highest mountain on Java Island was still ongoing,” 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 conduct 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 conduct activities within 500 metres of the riverbank along Besuk Kobokan because of the potential for being affected by the expansion of pyroclastic flows and lava flows up to a distance of 17 km from the summit,” he said.

Furthermore, the public must not conduct activities within a 5 km radius of the crater or summit of Mount Semeru because of the danger of ejected incandescent rocks.

The public is also urged to remain alert to the potential for pyroclastic flows, lava avalanches, and lahars along 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,” said Liswanto.