Volcano Mahameru Outburst in the Southeast Asian nation Triggers Evacuations

The nation's Semeru volcano, the tallest summit on Java island, has erupted, blanketing multiple communities with falling ash, prompting evacuations and leading authorities to raise the alert to the highest level.

The volcano in East Java province released blistering plumes of hot ash and a combination of stone, molten rock, and gases that travelled up to 4 miles down its sides multiple times from noon to dusk, while a thick column of fiery clouds rose 2km into the sky, as stated by Indonesia’s Geology Agency.

The outbursts that unfolded throughout the day forced authorities to raise the volcano’s alert level twice, from the level three to the highest, the agency said. No deaths or injuries have been reported.

More than 300 residents in the three communities most at risk in the district of Lumajang region were evacuated to government shelters, according to a spokesperson for the national emergency management body.

He said that increased activity of the volcano on Wednesday afternoon prompted authorities to widen the danger zone to 5 miles from the summit. People were advised to stay clear from an zone along the Besuk Kobokan River, which is the route of the molten rock stream, as scorching gases flowed down the volcano's sides.

Videos on social media displayed a dense cloud of volcanic dust sweeping through a wooded ravine to a waterway beneath a overpass. Residents, some with faces smeared with ash and rain, escaped to temporary shelters or departed for other safe areas.

Local media indicated that emergency teams were struggling to rescue about 178 people trapped on the 3,676-metre peak at the Ranu Kumbolo monitoring post. The group included 137 hikers, 15 carriers, seven guides and six tourism officials, according to an spokesperson with the national park.

“They are currently safe at Ranu Kumbolo monitoring post,” an official said in a recorded message. He said the post was situated 4.5km from the crater on the north side of the volcano, which is not in the path of the hot cloud flow that was observed traveling to the south-southeast. Bad weather and precipitation 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 many of the 129 live volcanoes in the archipelago, tens of thousands of residents continue to reside on its productive highlands.

Semeru’s last major eruption was in December 2021, when 51 people were lost their lives and hundreds others were burned and villages were submerged in layers of mud. The event forced the relocation of more than 10,000 residents from their houses.

The country, an archipelago of over 280 million inhabitants, sits along the Pacific “ring of fire”, a curved series of fault lines, and is susceptible to seismic events and volcanic activity.