Mount Semeru erupts with 1km-high ash column above summit

Lumajang, East Java (ANTARA) - Mount Semeru, located on the border of Lumajang and Malang regencies in East Java, erupted with a 1km-high ash column above the summit on Saturday evening.

“An eruption occurred at 16:57 WIB with an observed ash column height of approximately 1km above the summit, or 4,676 metres above sea level,” said Mukdas Sofian, a Mount Semeru Observation Post officer, in a written report received in Lumajang on Saturday.

He noted that the ash column was dense, white to grey in colour, blowing westward. The eruption was recorded on the seismograph with a maximum amplitude of 22mm and duration of 171 seconds.

According to the officer’s records, Mount Semeru erupted three times on Saturday: at 01:04 WIB with no visible eruption, followed by another at 04:53 WIB with no visible eruption, and the third at 16:57 WIB with a 1km-high eruption above the summit.

Mukdas explained that the current volcanic activity is at Level III (Alert) status, advising the public not to conduct any activities in the southeastern sector along the Besuk Kobokan area within 13 km from the summit (eruption centre).

“Beyond this distance, residents should avoid activities within 500 metres of riverbanks along the Besuk Kobokan due to the risk of pyroclastic flows and lahars extending up to 17 km from the summit,” he said.

He stated that people must not engage in activities within a 5 km radius of the crater/summit due to the danger of incandescent rock ejections.

“Residents should also remain vigilant for potential pyroclastic flows, rockfalls, and lahars along rivers and valleys originating from Mount Semeru, particularly along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat,” he added.

He further noted that potential lahars should be monitored in smaller rivers that are tributaries of Besuk Kobokan.