Volcano Semeru Outburst in Indonesia Prompts Emergency Relocations

The nation's Mount Semeru, the highest peak on Java island, has erupted, blanketing several villages with volcanic ash, leading to evacuations and causing officials to elevate the alert to the maximum level.

The mountain in East Java province released searing clouds of fiery ash and a mixture of rock, lava and gas that travelled up to 4 miles down its sides several times from noon to dusk, while a thick column of hot clouds rose 1.2 miles into the sky, according to Indonesia’s Geology Agency.

The eruptions that unfolded throughout the day forced officials to increase the mountain's warning status on two occasions, from the level three to the top level, the agency said. No casualties have been announced.

More than 300 inhabitants in the three villages most at risk in the district of Lumajang region were evacuated to official safe havens, as mentioned by a spokesperson for the national disaster mitigation agency.

He stated that increased activity of the volcano on the afternoon of Wednesday led authorities to expand the hazard area to 8km from the crater. Residents were urged to keep away from an zone along the Besuk Kobokan River, which is the route of the molten rock stream, as scorching gases flowed down Semeru’s slopes.

Footage on social media showed a thick plume of volcanic dust moving through a forested valley to a river beneath a bridge. Residents, some with faces smeared with ash and rain, escaped to temporary shelters or departed for alternative secure locations.

Regional news outlets reported that authorities were facing challenges to rescue about 178 individuals stranded on the 3,676-metre peak at the Ranu Kumbolo observation station. The group comprised 137 climbers, 15 carriers, seven guides and six travel representatives, according to an official with the protected area.

“They are currently safe at Ranu Kumbolo monitoring post,” an official said in a video statement. He noted the station was situated 4.5km from the summit on the north side of the volcano, which is not in the path of the fiery cloud movement that was seen moving to the south-southeast. Inclement conditions and precipitation forced the group to remain overnight there, he added.

The volcano, also called Great Mountain, has burst many occasions in the last two centuries. However, as is the situation with many of the 129 active volcanoes in Indonesia, tens of thousands of people continue to live on its fertile slopes.

The mountain's previous significant explosion was in late 2021, when 51 individuals were killed and several hundred more were burned and settlements were submerged in thick mud. The eruption forced the evacuation of more than 10,000 residents from their homes.

The country, an archipelago of over 280 million inhabitants, sits along the Pacific “ring of fire”, a horseshoe-shaped series of tectonic boundaries, and is susceptible to earthquakes and volcanic activity.