Mount Semeru Erupted Again This Morning, Spouting Ash Column 800 Meters High

LUMAJANG - Mount Semeru in East Java spewed volcanic material again on Tuesday morning. Officials recorded the eruption column reaching 800 meters above the summit, although the volcano's alert status remains at Alert Level II.

Mount Semeru Observation Post officer, Sigit Rian Alfian, reported the eruption occurred at 6:11 a.m. Western Indonesian Time (WIB).

"Mount Semeru erupted on Tuesday, November 18, 2025, at 6:11 a.m. Western Indonesian Time," Sigit said in a written statement received in Lumajang today.

The eruption produced an ash column observed as high as approximately 800 meters above the summit, or a total height of 4,476 meters above sea level (masl).

"The ash column was observed to be white to gray in color with a thick intensity directed southward. The eruption was recorded on a seismograph with a maximum amplitude of 22 mm and a duration of 112 seconds," Sigit explained.

PVMBG Issues Several Strict Recommendations

Although Mount Semeru is currently at Alert or Level II status, the Center for Volcanology and Geological Hazard Mitigation (PVMBG) has issued several crucial recommendations to the public to avoid the danger zone:

Besuk Kobokan Route: The public is strictly prohibited from engaging in any activity in the southeastern sector, along Besuk Kobokan, within eight kilometers of the summit (the eruption center).

Hot Cloud Expansion Alert: Beyond this distance, activities are prohibited within 500 meters of the riverbank along Besuk Kobokan. This is to anticipate the potential expansion of the pyroclastic flow and lava flows up to 13 kilometers from the summit.

Crater Radius: The public is advised to avoid activities within a three-kilometer radius of the crater or summit of Mount Semeru due to the risk of ejected incandescent rocks.

Potential for Rainfall Lava: The public is also asked to be aware of the potential for pyroclastic flows, lava avalanches, and rainfall lava along rivers and valleys that originate at the summit of Mount Semeru. Areas to watch out for include Besuk Kobokan, Besuk Bang, Besuk Kembar, and Besuk Sat, as well as tributaries of Besuk Kobokan.