Volcano Mahameru Eruption in Indonesia Triggers Emergency Relocations

Indonesia's Semeru volcano, the highest peak on the island of Java, has exploded, blanketing several villages with volcanic ash, leading to 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 mixture of rock, lava and gas that moved up to 7km down its sides several times from midday to evening, while a thick column of hot clouds rose 2km into the sky, according to Indonesia’s Geology Agency.

The outbursts that occurred 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 announced.

Over three hundred residents in the three communities most endangered in the district of Lumajang were relocated to official safe havens, according to a representative for the national disaster mitigation agency.

He stated that increased activity of the mountain on Wednesday afternoon prompted officials to expand the hazard area to 8km from the crater. Residents were urged to stay clear from an zone along the Kobokan River, which is the route of the lava flow, as scorching gases flowed down the volcano's sides.

Videos on online platforms showed a dense cloud of volcanic dust moving through a wooded ravine to a river beneath a overpass. Residents, some with faces covered with volcanic dust and rain, fled to makeshift refuges or left for alternative secure locations.

Local media indicated that emergency teams were facing challenges to rescue about 178 individuals trapped on the 3,676-metre mountain at the Ranu Kumbolo observation station. The group comprised 137 climbers, 15 carriers, seven escorts and six travel representatives, according to an spokesperson with the national park.

“They remain secure at Ranu Kumbolo monitoring post,” an official stated in a video statement. He noted the station was situated 4.5km from the crater on the northern slope of the mountain, which is not in the path of the hot cloud flow that was seen traveling to the southeast direction. Inclement conditions and rain forced the group to spend the night there, he added.

Semeru, also called Great Mountain, has burst numerous times in the past 200 years. Still, as is the situation with many of the 129 live volcanoes in Indonesia, thousands of people still to live on its productive highlands.

The mountain's last major eruption was in late 2021, when 51 people were lost their lives and several hundred more were injured and settlements were buried in layers of mud. The eruption led to the relocation of more than 10,000 people from their houses.

The country, an island chain of more than 280 million inhabitants, is located along the Pacific “ring of fire”, a horseshoe-shaped series of tectonic boundaries, and is prone to seismic events and volcanic activity.