Volcano Semeru Outburst in Indonesia Prompts Evacuations

The nation's Semeru volcano, the highest peak on Java island, has exploded, covering multiple communities with volcanic ash, leading to evacuations and leading authorities to raise the warning to the maximum level.

The mountain in the province of East Java released searing clouds of hot ash and a combination of stone, molten rock, and gases that travelled up to 7km down its slopes several times from midday to evening, while a thick column of hot clouds rose 2km into the air, according to Indonesia’s Geology Agency.

The outbursts that unfolded throughout the day compelled authorities to increase the volcano’s alert level twice, from the level three to the top level, the authority said. No casualties have been reported.

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 emergency management body.

He stated that increased activity of the volcano on the afternoon of Wednesday prompted authorities to widen the hazard area to 8km from the crater. People were urged to keep away from an area along the Besuk Kobokan River, which is the path of the molten rock stream, as searing gas moved down Semeru’s slopes.

Videos on social media showed a dense cloud of volcanic dust sweeping through a forested valley to a river beneath a overpass. Locals, some with faces smeared with ash and rain, escaped to temporary shelters or departed for alternative secure locations.

Local media reported that emergency teams were struggling to rescue about 178 people trapped on the 12,060-foot mountain at the Ranu Kumbolo observation station. The group comprised 137 climbers, 15 carriers, seven escorts and six tourism officials, according to an official with the protected area.

“They remain secure at Ranu Kumbolo monitoring post,” a spokesperson stated in a recorded message. He noted the post was located 4.5km from the crater on the northern slope of the mountain, which is not in the path of the hot cloud flow that was seen moving to the southeast direction. Inclement conditions and rain forced the group to remain overnight there, he explained.

Semeru, also known as Great Mountain, has burst numerous times in the past 200 years. Still, as is the case with many of the 129 active volcanoes in the archipelago, tens of thousands of people still to reside on its productive highlands.

Semeru’s previous significant explosion was in December 2021, when 51 individuals were lost their lives and hundreds others were injured and villages were buried in layers of mud. The eruption led to the relocation of over ten thousand people from their houses.

The country, an archipelago of more than 280 million inhabitants, sits along the Pacific seismic belt, a curved series of tectonic boundaries, and is prone to earthquakes and volcanic activity.