Volcano Mahameru Outburst in Indonesia Triggers Emergency Relocations

Indonesia's Semeru volcano, the tallest summit on the island of Java, has exploded, covering several villages with falling ash, prompting evacuations and causing officials to elevate the warning to the highest level.

The volcano in the province of East Java released blistering plumes of hot ash and a combination of rock, lava and gas that moved up to 7km down its slopes multiple times from midday to evening, while a thick column of hot clouds rose 2km into the air, as stated by Indonesia’s Geology Agency.

The eruptions that unfolded throughout the day forced authorities to raise the mountain's warning status twice, from the third-highest level to the highest, the agency said. No casualties have been announced.

More than 300 residents in the three villages most at risk in the area of Lumajang were evacuated to government shelters, according to a representative for the national emergency management body.

He stated that heightened volcanic movements of the mountain on Wednesday afternoon prompted officials to widen the danger zone to 8km from the crater. Residents were urged to stay clear from an area along the Besuk Kobokan River, which is the path of the lava flow, as searing gas flowed down the volcano's sides.

Footage on social media displayed a dense cloud of volcanic dust moving through a wooded ravine to a river beneath a overpass. Residents, some with faces smeared with ash and rain, escaped to makeshift refuges or left for other safe areas.

Regional news outlets reported that emergency teams were facing challenges to rescue about 178 individuals stranded on the 3,676-metre mountain at the Ranu Kumbolo monitoring post. The group comprised 137 hikers, 15 carriers, seven escorts and six travel representatives, according to an official with the protected area.

“They are currently safe at Ranu Kumbolo monitoring post,” a spokesperson said in a recorded message. He noted the post was located 2.8 miles from the crater on the northern slope of the volcano, which is not in the path of the fiery cloud movement that was seen moving to the south-southeast. Bad weather and rain forced the team to spend the night there, he explained.

The volcano, also called Mahameru, has burst numerous times in the last two centuries. Still, as is the situation with numerous of the 129 active volcanoes in Indonesia, thousands of residents continue to live on its fertile slopes.

Semeru’s last major eruption was in late 2021, when 51 individuals were killed and hundreds others were burned and settlements were submerged in layers of mud. The eruption led to the evacuation of more than 10,000 people from their homes.

The country, an island chain of more than 280 million inhabitants, sits along the Pacific seismic belt, a curved series of tectonic boundaries, and is susceptible to earthquakes and volcanism.