Mount Semeru Outburst in Indonesia Triggers Evacuations

The nation's Mount Semeru, the highest peak on the island of Java, has erupted, covering several villages with volcanic ash, prompting evacuations and leading authorities to raise the alert to the highest level.

The mountain in East Java province unleashed blistering plumes of hot ash and a combination of rock, lava and gas that moved up to 7km down its slopes several times from midday to evening, while a thick column of fiery clouds rose 1.2 miles into the sky, according to the nation's geological authority.

The outbursts that unfolded throughout the day forced officials to raise the volcano’s alert level twice, from the third-highest level to the top level, the agency said. No deaths or injuries have been reported.

More than 300 residents in the three villages most endangered in the district of Lumajang were evacuated to government shelters, according to a spokesperson for the national emergency management body.

He stated that increased activity of the mountain on Wednesday afternoon led authorities to expand the danger zone to 5 miles from the crater. People were urged to keep away from an zone along the Besuk Kobokan River, which is the path of the molten rock stream, as scorching gases moved down the volcano's sides.

Footage on online platforms showed a thick plume of volcanic dust sweeping through a wooded ravine to a river beneath a bridge. Locals, some with faces smeared with ash and water, escaped to makeshift refuges or left for other safe areas.

Regional news outlets reported that emergency teams were facing challenges to rescue about 178 people trapped on the 3,676-metre peak at the Ranu Kumbolo monitoring post. The group included 137 hikers, 15 carriers, seven escorts 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 video statement. He noted the post was situated 4.5km from the summit on the northern slope of the volcano, which is not in the path of the fiery cloud movement that was observed traveling to the south-southeast. Inclement conditions and precipitation forced the team to remain overnight there, he explained.

Semeru, also called Great Mountain, has erupted many occasions in the last two centuries. Still, as is the case with many of the 129 live volcanoes in the archipelago, tens of thousands of residents still to reside on its productive highlands.

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

The country, an island chain of more than 280 million inhabitants, sits along the Pacific “ring of fire”, a curved series of tectonic boundaries, and is prone to seismic events and volcanism.