Volcano Semeru Outburst in Indonesia Triggers Emergency Relocations

The nation's Semeru volcano, the tallest summit on Java island, has exploded, covering multiple communities with volcanic ash, leading to evacuations and leading authorities to raise the warning to the highest level.

The volcano in East Java province unleashed blistering plumes of hot ash and a mixture of rock, lava and gas that moved up to 7km down its sides several times from midday to evening, while a dense plume of fiery clouds rose 2km into the air, as stated by Indonesia’s Geology Agency.

The outbursts that occurred throughout the day compelled officials to increase the mountain's warning status twice, from the third-highest level to the top level, the agency said. No casualties have been reported.

Over three hundred residents in the three villages most at risk in the district of Lumajang region were relocated to official safe havens, as mentioned by a spokesperson for the national disaster mitigation agency.

He said that increased activity of the mountain on Wednesday afternoon prompted authorities to widen the hazard area to 8km from the crater. People were advised to keep away from an zone along the Besuk Kobokan River, which is the path of the molten rock stream, as scorching gases flowed down the volcano's sides.

Footage on social media displayed a thick plume of volcanic dust sweeping through a forested valley to a river beneath a overpass. Locals, some with faces covered with volcanic dust and rain, escaped to makeshift refuges or departed for other safe areas.

Local media reported that authorities were facing challenges to save about 178 individuals trapped on the 3,676-metre peak at the Ranu Kumbolo observation station. The group comprised 137 hikers, 15 porters, seven guides and six travel representatives, according to an spokesperson with the protected area.

“They remain secure at the Ranu Kumbolo station,” a spokesperson stated in a recorded message. He noted the station was located 4.5km from the crater on the north side of the mountain, which is outside the trajectory of the fiery cloud movement that was observed moving to the southeast direction. Bad weather and rain forced the team to remain overnight there, he added.

Semeru, also known as Great Mountain, has erupted many occasions in the past 200 years. Still, as is the case with numerous of the 129 live volcanoes in the archipelago, tens of thousands of people still to reside on its productive highlands.

Semeru’s previous significant explosion was in December 2021, when 51 individuals were killed and several hundred others were injured and villages were buried in layers of mud. The event led to the relocation of over ten thousand residents from their houses.

The country, an island chain of more than 280 million people, is located along the Pacific seismic belt, a horseshoe-shaped series of tectonic boundaries, and is prone to earthquakes and volcanism.