Volcano Mahameru Outburst in Indonesia Prompts Emergency Relocations

The nation's Mount Semeru, the highest peak on Java island, has erupted, covering multiple communities with falling ash, prompting evacuations and causing officials to elevate the alert to the maximum level.

The mountain in the province of East Java unleashed blistering plumes of hot ash and a combination of stone, molten rock, and gases that travelled up to 4 miles down its slopes multiple times from noon to dusk, while a thick column of hot clouds rose 2km into the air, as stated by the nation's geological authority.

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

Over three hundred inhabitants in the three communities most at risk in the area of Lumajang were evacuated to government shelters, according to a representative for the national disaster mitigation agency.

He stated that heightened volcanic movements of the volcano on Wednesday afternoon led authorities to widen the danger zone to 5 miles from the crater. People were urged to stay clear from an area along the Kobokan River, which is the path of the lava flow, as scorching gases flowed down Semeru’s slopes.

Footage on online platforms displayed a thick plume of ash moving through a forested valley to a river beneath a bridge. Residents, some with faces covered with volcanic dust and rain, escaped to makeshift refuges or departed for other safe areas.

Local media reported that emergency teams were struggling to save about 178 people trapped on the 3,676-metre mountain at the Ranu Kumbolo observation station. The party included 137 hikers, 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,” a spokesperson said in a recorded message. He said the post was located 2.8 miles from the crater on the northern slope of the volcano, which is outside the trajectory of the hot cloud flow that was observed moving to the southeast direction. Inclement conditions and rain required the team to spend the night there, he added.

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

Semeru’s last major eruption was in December 2021, when 51 people were lost their lives and hundreds more were injured and settlements were buried in layers of mud. The event led to the evacuation of over ten thousand people from their homes.

The country, an island chain of over 280 million people, sits along the Pacific seismic belt, a horseshoe-shaped series of fault lines, and is susceptible to seismic events and volcanism.