Eruption of Mount Semeru, Hot Clouds Launched 3,500 Meters

The eruption of Mount Semeru was accompanied by hot clouds falling with a glide distance of 3,500 meters towards Besuk Kobokan on Sunday (29/3/2026). ANTARA/HO-PVMBG

JAKARTA - Mount Semeru, which is on the border of Lumajang and Malang Regencies, East Java, erupted accompanied by a hot cloud falling with a glide distance of 3,500 meters towards Besuk Koboan on Sunday, March 29.

"There has been an eruption of Mount Semeru at 08.49 WIB with an ash column height of 800 meters above the peak or 4,476 meters above sea level (msl)," said Mount Semeru Observation Post Officer Mukdas Sofian in a written report received in Lumajang, Sunday, quoted by Antara.

According to him, the observed ash column was white to gray with a thick intensity leaning towards the southwest. The eruption was recorded on the seismogram with a maximum amplitude of 22 mm and a duration of about 4 minutes 6 seconds.

"The eruption of the highest mountain on Java Island was accompanied by a hot cloud falling with a glide distance of 3,500 meters towards Besuk Kobokan," he said.

Based on the officers' records, the mountain, which has a height of 3,676 meters above sea level, has been recorded as having experienced nine eruptions on Sunday since 00.21 WIB with an eruption column height of 800 meters above the peak and the 9th eruption occurred at 08.49 WIB accompanied by hot clouds.

The eruption with the highest eruption occurred at 01.01 WIB with the height of the observed eruption column about 1,000 meters above the peak and the ash column was observed to be white to gray with medium intensity towards the southwest. When the report was made, the eruption was still ongoing.

Mukdas explained that currently Mount Semeru is in a volcanic activity status Level III (Alert), so the recommendation for the public is not to carry out any activities in the southeast sector along Besuk Kobokan, as far as 13 km from the peak (center of the eruption).

Outside this distance, the public should not carry out activities at a distance of 500 meters from the river bank (river border) along Besuk Kobokan because they have the potential to be hit by the expansion of the hot cloud and lava flow up to a distance of 17 km from the peak.

"The public is prohibited from carrying out activities within a radius of 5 km from the crater/peak of Mount Semeru because they are prone to the danger of stone throwing (pijar)," he said.

He also appealed to the public to be aware of the potential for hot clouds, lava discharge, and lahar along the river/valley flows upstream of the Semeru Volcano peak, especially along Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as the potential for lahar in small rivers which are tributaries of Besuk Kobokan.