Volcano Semeru Outburst in Indonesia Prompts Evacuations

The nation's Mount Semeru, the highest peak on Java island, has erupted, blanketing multiple communities with volcanic ash, leading to evacuations and causing officials to elevate the warning to the maximum level.

The volcano in the province of East Java released blistering plumes of hot ash and a combination of stone, molten rock, and gases that travelled up to 7km down its slopes multiple times from midday to evening, while a dense plume of fiery clouds rose 2km into the sky, as stated by Indonesia’s Geology Agency.

The eruptions that occurred throughout the day forced authorities to increase the volcano’s alert level on two occasions, from the third-highest level to the highest, the authority reported. No casualties have been reported.

More than 300 inhabitants in the three communities most at risk in the area of Lumajang region were evacuated to official safe havens, according to a representative for the national disaster mitigation agency.

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

Footage on social media displayed a thick plume of ash moving through a forested valley to a waterway beneath a overpass. Residents, some with faces covered with ash and water, escaped to makeshift refuges or left for alternative secure locations.

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

“They remain secure at the Ranu Kumbolo station,” an official stated in a video statement. He said the post was situated 2.8 miles from the summit on the north side of the volcano, which is not in the path of the hot cloud flow that was observed moving to the southeast direction. Inclement conditions and rain forced the team to spend the night there, he added.

The volcano, also known as Great Mountain, has erupted numerous times in the past 200 years. Still, as is the situation with many of the 129 live volcanoes in the archipelago, thousands of residents continue to live on its productive highlands.

Semeru’s last major eruption was in December 2021, when 51 people were killed and several hundred more were burned and villages were buried in layers of mud. The event forced the evacuation of more than 10,000 people from their homes.

The country, an archipelago of over 280 million people, is located along the Pacific “ring of fire”, a horseshoe-shaped series of fault lines, and is prone to seismic events and volcanism.