Volcano Mahameru Outburst in Indonesia Prompts Emergency Relocations

The nation's Mount Semeru, the highest peak on Java island, has erupted, blanketing multiple communities with volcanic ash, leading to evacuations and leading authorities to raise the alert to the maximum level.

The mountain in East Java province released blistering plumes of hot ash and a mixture of rock, lava and gas that moved up to 4 miles down its slopes several times from midday to evening, while a dense plume of hot clouds rose 2km into the air, as stated by the nation's geological authority.

The eruptions that occurred throughout the day forced authorities to increase the volcano’s alert level twice, from the level three to the top level, the agency reported. No casualties have been announced.

More than 300 inhabitants in the three villages most at risk in the area of Lumajang region were evacuated to government shelters, according to a spokesperson for the national disaster mitigation agency.

He stated that heightened volcanic movements of the mountain on the afternoon of Wednesday led authorities to expand the hazard area to 5 miles from the summit. Residents were advised 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 social media showed a dense cloud of volcanic dust sweeping through a forested valley to a river beneath a bridge. Residents, some with faces smeared with volcanic dust and water, escaped to temporary shelters or departed for other safe areas.

Regional news outlets reported that emergency teams were struggling to save about 178 people stranded on the 3,676-metre mountain at the Ranu Kumbolo monitoring post. The group included 137 climbers, 15 carriers, seven guides and six tourism officials, according to an spokesperson with the protected area.

“They remain secure at Ranu Kumbolo monitoring post,” an official stated in a video statement. He said the post was located 4.5km from the crater on the northern slope of the mountain, which is outside the trajectory of the fiery cloud movement that was seen traveling to the south-southeast. Bad weather and rain required the team to remain overnight there, he explained.

Semeru, also known as Great Mountain, has erupted many occasions in the last two centuries. Still, as is the case with numerous of the 129 active volcanoes in the archipelago, tens of thousands of people continue to live on its fertile slopes.

Semeru’s previous significant explosion was in late 2021, when 51 people were lost their lives and several hundred others were burned and settlements were submerged in thick mud. The event forced the relocation of more than 10,000 people from their houses.

The country, an island chain of more than 280 million people, is located along the Pacific seismic belt, a horseshoe-shaped series of tectonic boundaries, and is prone to earthquakes and volcanism.