Indonesia’s highest peak on Java island, Mount Semeru, erupted on Wednesday, spreading ash over several villages and triggering evacuations as authorities raised the alert level to its maximum. The volcano in East Java province released hot ash clouds, along with a mix of rock, lava, and gas, reaching up to seven kilometers down its slopes multiple times from midday until dusk. Indonesia’s Geology Agency reported a two-kilometer high column of hot clouds rising into the sky.
Due to the ongoing eruptions, the volcano’s alert level was raised twice throughout the day, escalating from the third-highest level to the highest. Thankfully, there have been no reports of casualties. Over 300 residents from the most vulnerable villages in the Lumajang district were relocated to government shelters by the National Disaster Mitigation Agency.
The increased volcanic activity on Wednesday afternoon prompted authorities to expand the danger zone to eight kilometers from the crater. People were warned to stay away from the area along the Besuk Kobokan River, which was in the path of the lava flow as scorching gas streamed down Semeru’s slopes.
Videos shared on social media depicted a dense ash cloud sweeping through a forested valley towards a river under a bridge. Evacuees, some covered in volcanic dust and rain, sought refuge in temporary shelters or moved to safer locations. Local reports indicated that around 178 individuals, including climbers, porters, guides, and tourism officials, were stranded at the Ranu Kumbolo monitoring post on the 3,676-meter mountain.
Despite the challenging conditions, the group was reported as safe at the monitoring post, located 4.5 kilometers from the crater on the northern slope of the mountain, away from the path of the observed hot cloud flow. The adverse weather conditions forced them to spend the night there. Mount Semeru, also known as Mahameru, has a history of eruptions over the past two centuries, like many of Indonesia’s 129 active volcanoes.
The last significant eruption of Semeru occurred in December 2021, resulting in fatalities and injuries, forcing the evacuation of thousands of people. The Indonesian archipelago, home to over 280 million people, is situated along the Pacific “Ring of Fire,” making it susceptible to seismic and volcanic events.
