Mount Mahameru Eruption in Indonesia Triggers Evacuations

Indonesia's Mount Semeru, the tallest summit on Java island, has erupted, covering several villages with falling ash, prompting evacuations and leading authorities to raise the warning to the maximum level.

The volcano in the province of East Java released searing clouds of hot ash and a mixture of stone, molten rock, and gases that travelled up to 4 miles down its sides multiple times from midday to evening, while a thick column of hot clouds rose 2km into the sky, as stated by Indonesia’s Geology Agency.

The eruptions that unfolded throughout the day compelled authorities to raise the volcano’s alert level twice, from the third-highest level to the highest, the authority said. No casualties have been reported.

More than 300 residents in the three villages most at risk in the district of Lumajang were evacuated to official safe havens, according to a representative for the national emergency management body.

He said that heightened volcanic movements of the volcano on the afternoon of Wednesday prompted officials to expand the hazard area to 8km from the crater. People were urged to stay clear from an zone along the Kobokan River, which is the path of the molten rock stream, as searing gas flowed down Semeru’s slopes.

Footage on online platforms showed a thick plume of volcanic dust sweeping through a forested valley to a waterway beneath a overpass. Residents, some with faces smeared with ash and water, fled to temporary shelters or departed for other safe areas.

Local media indicated that authorities were struggling to save about 178 individuals stranded on the 3,676-metre mountain 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 national park.

“They remain secure at Ranu Kumbolo monitoring post,” a spokesperson said in a video statement. He said the station was situated 2.8 miles from the summit on the north side of the volcano, which is not in the path of the hot cloud flow that was observed moving to the southeast direction. Bad weather and rain required the team to spend the night there, he added.

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

Semeru’s previous significant explosion was in December 2021, when 51 people were killed and several hundred others were burned and villages were buried in thick mud. The event forced the evacuation of over ten thousand people from their houses.

The country, an island chain of over 280 million people, sits along the Pacific “ring of fire”, a curved series of tectonic boundaries, and is prone to seismic events and volcanic activity.