Indonesia’s Mt Semeru eruption buries homes, damages bridge

Villagers inspect an area affected by the eruption of Mt Semeru in Kajar Kuning village in Lumajang, East Java, Indonesia. Photo / AP

Improved weather conditions have allowed rescuers to resume evacuation efforts and a search for possible victims after the highest volcano on Indonesia’s most densely populated island erupted, triggered by monsoon rains.

Mt Semeru in Lumajang district in East Java province spewed thick columns of ash more than 1500m into the sky on Monday. Villages and nearby towns were blanketed with falling ash, blocking out the sun, but no casualties have been reported.

Hundreds of rescuers were deployed in the worst-hit villages of Sumberwuluh and Supiturang, where houses and mosques were buried to their rooftops by tonnes of volcanic debris.

Heavy rains had eroded and finally collapsed the lava dome atop the 3676m volcano, causing an avalanche of blistering gas and lava down its slopes toward a nearby river. Searing gas raced down the sides of the mountain, smothering entire villages and destroying a bridge that had just been rebuilt after a powerful eruption last year.

A man looks on as Mt Semeru releases volcanic materials during the eruption. Photo / AP

Semeru’s last major eruption was in December 2021, when it blew up with a fury that left 51 people dead in villages that were buried in layers of mud. Several hundred others suffered serious burns and the eruption forced the evacuation of more than 10,000 people. The Government moved about 2970 houses out of the danger zone, including from Sumberwuluh village.

Lumajang district chief Thoriqul Haq said villagers who are still haunted by last year’s eruption fled on their own when they heard the mountain start to rumble early in the morning, so “casualties could be avoided.”

“They have learned an important lesson on how to avoid the danger of eruption,” he said while inspecting a damaged bridge in Kajar Kuning hamlet.

He said nearly 2000 people escaped to emergency shelters at several schools, but many have returned to their homes tonight to tend their livestock and protect their property.

People inspect their ash-covered village following the eruption of Mt Semeru. Photo / AP

Increased volcanic activity in the afternoon prompted authorities to widen the danger zone to 8km from the crater, and scientists raised the volcano’s alert level to the highest, said Hendra Gunawan, who heads the Volcanology and Geological Hazard Mitigation Centre.

People were advised to keep off the southeastern sector along the Besuk Kobokan River, which is in the path of the lava flow.

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

Indonesia, an archipelago of more than 270 million people, sits along the Pacific “Ring of Fire,” a horseshoe-shaped series of fault lines, and is prone to earthquakes and volcanic activity.