Mount Semeru Outburst in Indonesia Prompts Evacuations

Indonesia's Mount Semeru, the tallest summit on the island of Java, has exploded, blanketing multiple communities with volcanic ash, prompting evacuations and leading authorities to raise the alert to the highest level.

The mountain in the province of East Java released searing clouds of hot ash and a mixture of rock, lava and gas that travelled up to 7km down its slopes several times from noon to dusk, while a dense plume of fiery clouds rose 1.2 miles into the sky, as stated by the nation's geological authority.

The eruptions that unfolded throughout the day compelled officials to increase the volcano’s alert level on two occasions, from the level three to the top level, the agency said. No casualties have been announced.

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

He stated that increased activity of the mountain on the afternoon of Wednesday led authorities to widen the hazard area to 5 miles from the summit. People were urged to keep away from an area along the Besuk Kobokan River, which is the path of the lava flow, as scorching gases flowed down Semeru’s slopes.

Footage on social media displayed a dense cloud of volcanic dust sweeping through a forested valley to a waterway beneath a overpass. Residents, some with faces smeared with volcanic dust and water, escaped to makeshift refuges or departed for other safe areas.

Local media reported that authorities were facing challenges to rescue about 178 people trapped on the 12,060-foot peak at the Ranu Kumbolo observation station. The group comprised 137 hikers, 15 carriers, seven guides and six travel representatives, according to an official with the protected area.

“They are currently safe at the Ranu Kumbolo station,” an official said in a video statement. He said the post was located 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 precipitation forced the group to spend the night there, he added.

Semeru, also called Mahameru, has erupted many occasions in the last two centuries. However, as is the situation with many of the 129 active volcanoes in Indonesia, thousands of residents continue to live on its fertile slopes.

The mountain's previous significant explosion was in December 2021, when 51 people were killed and hundreds more were burned and villages were buried in thick mud. The eruption forced the relocation of over ten thousand people from their homes.

Indonesia, an island chain of more than 280 million people, is located along the Pacific “ring of fire”, a curved series of fault lines, and is prone to earthquakes and volcanic activity.