Villages blanketed in ash as Semeru Volcano forces mass evacuations

Mount Semeru in East Java has entered a new phase of intense activity, prompting authorities to raise the alert level to its highest classification. The volcano released ash clouds reaching more than five kilometres into the atmosphere, while pyroclastic flows travelled up to seven kilometres downslope. These flows, composed of hot ash, rock fragments, and gas, moved rapidly through valleys and inundated parts of nearby settlements. More than 300 residents from high-risk villages were evacuated as a precaution.

Several villages near the volcano reported ash deposits, structural damage, and disruptions to transport routes. Houses in Supiturang and surrounding areas were partially buried by ash and volcanic debris. An elementary school also experienced severe damage. Search teams assisted hikers stranded at the Ranu Kumbolo monitoring post, which sits outside the primary flow path. Volcanic ash dispersion remained highly variable due to shifting weather conditions.

Semeru’s behaviour reinforces the need for continuous geotechnical assessment in volcanically active regions. Pyroclastic density currents, rapid ashfall, and secondary lahars create recurring challenges for slope stability and infrastructure resilience. Its last major eruption occurred in December 2021, resulting in 51 fatalities, widespread ash deposition across nearby villages, damage to more than 5,000 homes, and the displacement of nearly 10,000 residents.

Indonesia hosts nearly 130 active volcanoes, and Semeru’s frequent episodes demonstrate the importance of hazard zoning, evacuation planning, and reliable monitoring systems.

Check out the following video demonstrating the severe volcano eruption.