Wednesday morning, Semeru erupted twice, the highest eruption reached 900 meters

LUMAJANG - Mount Semeru, which is on the border of Lumajang and Malang Regencies, erupted again, accompanied by an eruption 900 meters above the peak and rumbling sounds on Wednesday, December 24 morning.

"There was an eruption of Mount Semeru on December 24, 2025 at 04.23 WIB with an observed eruption column height of about 900 meters above the peak or 4,576 meters above sea level (msl)," said Mount Semeru Observation Post Officer, Sigit Rian Alfian, quoted by Antara.

According to him, the observed ash column was white to gray with a thick intensity leaning towards the north and northeast.

The eruption was recorded on the seismograph with a maximum amplitude of 22 mm and a duration of about 2 minutes 28 seconds.

"The eruption of Mount Semeru that occurred this morning was accompanied by a weak rumbling sound," he said.

Based on data from officers, the highest mountain on Java was also recorded to have erupted at 01.39 WIB with an eruption height of 700 meters above the peak.

The observed ash column was white to gray with a thick intensity towards the northeast and the eruption was recorded on the seismograph with a maximum amplitude of 22 mm for 118 seconds.

Sigit explained that currently Mount Semeru is at level III (standby) status, so the Center for Volcanology and Geological Hazard Mitigation (PVMBG) has provided a number of recommendations.

"People should not do any activities in the southeast sector along Besuk Kobokan, as far as 13 km from the peak (the center of the eruption)," he said.

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 also 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).

Then residents need to be aware of the potential for hot clouds, lava discharge, and lahar along the river/valley flow upstream at the peak of the Semeru Volcano, 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.