Mount Semeru Eruption in Indonesia Prompts Emergency Relocations

Indonesia's Mount Semeru, the tallest summit on Java island, has exploded, covering several villages with volcanic ash, leading to evacuations and causing officials to elevate the alert to the maximum level.

The mountain in East Java province unleashed searing clouds of hot ash and a combination of stone, molten rock, and gases that moved up to 4 miles down its slopes multiple times from noon to evening, while a thick column of hot clouds rose 2km into the sky, according to the nation's geological authority.

The outbursts that occurred throughout the day forced authorities to raise the mountain's warning status twice, from the third-highest level to the top level, the agency said. No deaths or injuries have been reported.

Over three hundred residents in the three communities most endangered in the district of Lumajang region were relocated to government shelters, according to a spokesperson for the national emergency management body.

He said that increased activity of the mountain on Wednesday afternoon prompted authorities to widen the hazard area to 8km from the crater. People were advised to stay clear from an zone along the Besuk Kobokan River, which is the path of the lava flow, as scorching gases flowed down Semeru’s slopes.

Videos on social media showed a thick plume of volcanic dust sweeping through a wooded ravine to a river beneath a bridge. Residents, some with faces smeared with volcanic dust and rain, fled to makeshift refuges or departed for alternative secure locations.

Local media indicated that emergency teams were struggling to rescue about 178 individuals trapped on the 3,676-metre mountain at the Ranu Kumbolo observation station. The group comprised 137 hikers, 15 porters, seven guides and six travel representatives, according to an official with the national park.

“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 hot cloud flow that was seen traveling to the south-southeast. Bad weather and rain required the team to remain overnight there, he added.

Semeru, also called Mahameru, has erupted numerous times in the past 200 years. Still, as is the case with many of the 129 live volcanoes in Indonesia, thousands of residents continue to reside on its fertile slopes.

Semeru’s last major eruption was in late 2021, when 51 people were lost their lives and hundreds others were burned and settlements were buried in thick mud. The event led to the relocation of more than 10,000 people from their homes.

Indonesia, an island chain of more than 280 million people, sits along the Pacific “ring of fire”, a curved series of fault lines, and is susceptible to seismic events and volcanic activity.