Mount Mahameru Outburst in Indonesia Prompts Evacuations

The nation's Semeru volcano, the highest peak on the island of Java, has erupted, covering several villages with falling ash, leading to evacuations and leading authorities to raise the warning to the highest level.

The mountain in East Java province released blistering plumes of fiery ash and a mixture of rock, lava and gas that moved up to 7km down its slopes several times from noon to evening, while a dense plume of hot clouds rose 1.2 miles into the air, as stated by Indonesia’s Geology Agency.

The eruptions that unfolded throughout the day forced authorities to raise the volcano’s alert level on two occasions, from the level three to the highest, the agency said. No casualties have been reported.

More than 300 residents in the three villages most endangered in the district of Lumajang were evacuated to official safe havens, according to a representative for the national emergency management body.

He said that heightened volcanic movements of the mountain on the afternoon of Wednesday led authorities to expand the danger zone to 8km from the crater. People were advised to keep away from an area along the Kobokan River, which is the route of the molten rock stream, as searing gas moved down the volcano's sides.

Footage on social media displayed a thick plume of volcanic dust sweeping through a forested valley to a river beneath a bridge. Locals, some with faces covered with volcanic dust and water, escaped to makeshift refuges or departed for alternative secure locations.

Local media reported that authorities were struggling to save about 178 individuals trapped on the 12,060-foot mountain at the Ranu Kumbolo observation station. The group comprised 137 hikers, 15 porters, seven guides and six tourism officials, according to an official with the national park.

“They remain secure at Ranu Kumbolo monitoring post,” an official said in a video statement. He noted the post was situated 4.5km from the summit on the northern slope of the volcano, which is not in the path of the hot cloud flow that was seen traveling to the south-southeast. Bad weather and precipitation required the group to remain overnight there, he explained.

Semeru, also known as Great Mountain, has erupted many occasions in the last two centuries. However, as is the situation with numerous of the 129 active volcanoes in Indonesia, thousands of residents continue to reside on its fertile slopes.

The mountain's last major eruption was in late 2021, when 51 individuals were killed and several hundred more were burned and settlements were buried in layers of mud. The event led to the relocation of over ten thousand residents from their houses.

Indonesia, an archipelago of over 280 million people, is located along the Pacific “ring of fire”, a horseshoe-shaped series of fault lines, and is susceptible to seismic events and volcanic activity.