Volcano Semeru Eruption in the Southeast Asian nation Triggers Evacuations

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

The volcano in the province of East Java unleashed searing clouds of hot ash and a combination of stone, molten rock, and gases that travelled up to 4 miles down its slopes multiple times from midday to evening, while a dense plume of fiery clouds rose 1.2 miles into the air, according to the nation's geological authority.

The eruptions that occurred throughout the day forced authorities to raise the mountain's warning status on two occasions, from the third-highest level to the highest, the authority said. No casualties have been announced.

More than 300 residents in the three communities most endangered in the district of Lumajang region were evacuated to government shelters, according to a spokesperson for the national disaster mitigation agency.

He said that increased activity of the mountain on the afternoon of Wednesday led officials to widen the danger zone to 8km from the crater. Residents were advised to stay clear from an area along the Besuk Kobokan River, which is the route of the molten rock stream, as scorching gases flowed down Semeru’s slopes.

Videos on online platforms displayed a dense cloud of ash sweeping through a wooded ravine to a waterway beneath a overpass. Locals, some with faces smeared with ash and water, fled to makeshift refuges or departed for other safe areas.

Local media reported that emergency teams were facing challenges to rescue about 178 individuals trapped on the 3,676-metre mountain at the Ranu Kumbolo monitoring post. The party included 137 hikers, 15 porters, seven escorts and six tourism officials, according to an official with the protected area.

“They remain secure at Ranu Kumbolo monitoring post,” a spokesperson said in a recorded message. He noted 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 observed moving to the southeast direction. Bad weather and rain required the team to spend the night there, he explained.

The volcano, also called Mahameru, has burst many occasions in the past 200 years. However, as is the situation with many of the 129 live volcanoes in Indonesia, tens of thousands of people continue to live on its fertile slopes.

Semeru’s previous significant explosion was in December 2021, when 51 individuals were lost their lives and hundreds more were injured and villages were submerged in thick mud. The event forced the relocation of over ten thousand people from their houses.

The country, an archipelago of more than 280 million inhabitants, sits along the Pacific “ring of fire”, a curved series of tectonic boundaries, and is susceptible to earthquakes and volcanism.