Volcano Mahameru Outburst in Indonesia Prompts Emergency Relocations

The nation's Semeru volcano, the tallest summit on Java island, has exploded, blanketing several villages with volcanic ash, leading to evacuations and causing officials to elevate the warning to the highest level.

The volcano in East Java province unleashed blistering plumes of fiery ash and a mixture of rock, lava and gas that travelled up to 4 miles down its sides multiple times from midday to dusk, while a dense plume of hot clouds rose 1.2 miles into the sky, according to the nation's geological authority.

The eruptions that unfolded throughout the day forced authorities to increase the mountain's warning status on two occasions, from the third-highest level to the highest, the authority said. No deaths or injuries have been reported.

More than 300 inhabitants in the three villages most at risk in the area of Lumajang were evacuated to government shelters, according to a representative for the national emergency management body.

He stated that heightened volcanic movements of the volcano on Wednesday afternoon led officials to expand the hazard area to 8km from the crater. Residents were advised to keep away from an area along the Kobokan River, which is the route of the lava flow, as searing gas flowed down the volcano's sides.

Videos on online platforms displayed a thick plume of ash moving through a forested valley to a waterway beneath a bridge. Locals, some with faces covered with ash and water, escaped to makeshift refuges or left for alternative secure locations.

Local media reported that emergency teams were struggling to save about 178 individuals trapped on the 12,060-foot peak at the Ranu Kumbolo monitoring post. The party comprised 137 hikers, 15 porters, seven escorts and six travel representatives, according to an official with the national park.

“They are currently safe at the Ranu Kumbolo station,” an official said in a video statement. He said the post was situated 4.5km from the crater on the north side of the mountain, which is outside the trajectory of the hot cloud flow that was observed traveling to the south-southeast. Inclement conditions and precipitation forced the group to spend the night there, he explained.

The volcano, also called Mahameru, has burst numerous times in the last two centuries. However, as is the case with many of the 129 active volcanoes in Indonesia, tens of thousands of residents continue to reside on its productive highlands.

The mountain's previous significant explosion was in late 2021, when 51 individuals were lost their lives and several hundred others were burned and villages were buried in layers of mud. The event led to the relocation of more than 10,000 residents from their homes.

Indonesia, an archipelago of more than 280 million inhabitants, sits along the Pacific “ring of fire”, a horseshoe-shaped series of tectonic boundaries, and is prone to earthquakes and volcanism.