Indonesian authorities reported at least 41 fatalities and dozens missing after flash floods triggered by heavy rainfall and a cold lava flow from a volcano in West Sumatra province.
Devastating Impacts
The flash floods, which occurred on May 11, swept through villages on the slopes of Marapi volcano in four districts of West Sumatra. Abdul Muhari, spokesperson for Indonesia's National Disaster Management Agency, stated that the floods carried away dozens of people and submerged over 100 homes and public facilities. Cold lava, also known as lahar, is a volcanic material composed of ash, sand, and gravel carried down the volcano's slopes by rainwater.
According to Ilham Wahab, an official from the West Sumatra Disaster Mitigation Agency, "As of yesterday evening (May 12), our data recorded 37 fatalities. However, this morning (May 13), the number has increased to 41."
Rescue workers continue to search for 17 missing individuals, with 3 in Agam district and 14 in Tanah Datar district, the areas most heavily impacted by the floods, which affected hundreds of thousands of residents.
Infrastruktur Damaged
Kartyana Putra, Chief of Padang Panjang City Police, stated that the flash floods blocked major roads around the Anai Valley waterfall area in Tanah Datar district with mud, cutting off access to other cities. Videos released by Indonesia's National Search and Rescue Agency depicted roads submerged in water and mud.
The disaster occurred just two months after heavy rainfall triggered flash floods and landslides in West Sumatra's Pesisir Selatan and Padang Pariaman districts, killing at least 21 people and leaving five missing. In 2022, approximately 24,000 people were evacuated, and two children were killed during a major flood in Sumatra.
Active Volcano
Marapi is one of Indonesia's most active volcanoes. It has been active since an eruption in January 2023 that caused no casualties. In late last year, Marapi erupted, sending a massive plume of ash and dust 3,000 meters into the sky, killing at least 24 mountain climbers.
According to Indonesia's Volcanology and Geological Hazard Mitigation Center, the volcano has been on a Level 3 warning, the third highest of four alert levels, since 2011, indicating it is at an elevated level of activity and advising climbers and villagers to stay more than 3 kilometers from the summit to avoid potential hazards.
Marapi is known for its sudden and unpredictable eruptions due to its shallow and summit-close source. Its eruptions are not primarily driven by the deep movement of magma, causing them to be felt less on seismic instruments.
Indonesia, a nation highly susceptible to seismic activity, is located on the Pacific "Ring of Fire," a horseshoe-shaped arc of volcanoes and seismic fault lines encircling the Pacific Ocean.