Mount Mahameru Outburst in Indonesia Triggers Evacuations

The nation's Mount Semeru, the highest peak on the island of Java, has exploded, covering several villages with volcanic ash, prompting evacuations and leading authorities to raise the alert to the highest level.

The mountain in the province of East Java unleashed blistering plumes of fiery ash and a mixture of stone, molten rock, and gases that moved up to 7km down its slopes several times from noon to dusk, while a dense plume of hot clouds rose 1.2 miles into the sky, according to Indonesia’s Geology Agency.

The eruptions that unfolded throughout the day forced authorities to increase the volcano’s alert level twice, from the third-highest level to the highest, the authority said. No deaths or injuries have been announced.

More than 300 inhabitants in the three communities most at risk in the district of Lumajang were relocated to government shelters, according to a representative for the national emergency management body.

He stated that increased activity of the volcano on Wednesday afternoon prompted officials to widen the danger zone to 5 miles from the summit. Residents were urged to keep away from an area along the Besuk Kobokan River, which is the route of the molten rock stream, as scorching gases moved down Semeru’s slopes.

Videos on online platforms showed a thick plume of ash sweeping through a forested valley to a waterway beneath a overpass. Residents, some with faces covered with volcanic dust and water, escaped to temporary shelters or departed for other safe areas.

Local media reported that emergency teams were facing challenges to save about 178 individuals trapped on the 12,060-foot mountain at the Ranu Kumbolo observation station. The group comprised 137 hikers, 15 carriers, seven guides and six tourism officials, according to an official with the protected area.

“They are currently safe at the Ranu Kumbolo station,” a spokesperson said in a video statement. He said the station was located 4.5km from the crater on the north side of the mountain, which is not in the path of the hot cloud flow that was seen traveling to the south-southeast. Bad weather and rain required the group to remain overnight there, he added.

The volcano, also called Mahameru, has erupted numerous times in the past 200 years. Still, as is the situation with many of the 129 live volcanoes in Indonesia, thousands of people continue to reside on its fertile slopes.

The mountain's previous significant explosion was in late 2021, when 51 individuals were killed and several hundred others were injured and settlements were submerged in thick mud. The event forced the relocation of over ten thousand people from their houses.

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