Indonesian authorities reported on May 12 that flash floods caused by heavy rainfall and cold lava flows from a volcano in West Sumatra province have resulted in at least 41 fatalities and dozens of people missing.
Destruction in the area affected by flash floods in Agam district, West Sumatra, Indonesia. (Photo: Reuters).
According to AP, on the evening of May 11, hours of heavy rain combined with cold lava flows from Mount Marapi swept through villages located on the slopes in four districts of West Sumatra. Abdul Muhari, spokesperson for Indonesia’s National Disaster Management Agency, stated that the flash floods swept away dozens of residents and submerged over 100 houses and public facilities. Cold lava, also known as lahar, consists of volcanic materials such as ash, sand, and gravel washed down the volcanic slopes by rainwater.
Ilham Wahab, an official from the West Sumatra Disaster Mitigation Agency, told AFP: “As of last night (May 12), we recorded 37 fatalities. But as of this morning (May 13), that number has risen to 41.”
He noted that rescue teams are still searching for 17 other missing individuals, with 3 in Agam district and 14 in Tanah Datar district. These are the two areas most severely affected by the flash floods, home to hundreds of thousands of people.
Aerial view of a district affected by flash floods in West Sumatra, Indonesia. (Photo: Indonesia National Disaster Management Agency).
Kartyana Putra, the police chief of Padang Panjang, reported that the flash floods blocked major roads around the Anai Valley area in Tanah Datar district with mud, cutting off traffic to other cities. Videos recorded by the National Search and Rescue Agency of Indonesia show roads inundated with water and mud.
This disaster occurred just two months after heavy rainfall caused flash floods and landslides in the South Pesisir and Padang Pariaman districts of West Sumatra, resulting in at least 21 deaths and 5 missing persons. In 2022, approximately 24,000 people had to evacuate, and 2 children lost their lives in flooding on Sumatra Island.
Marapi is one of the most active volcanoes in Indonesia. The volcano has been erupting since January 2023 without causing casualties. At the end of last year, Marapi erupted, producing a massive ash plume that reached 3,000 meters, resulting in the deaths of at least 24 climbers.
According to the Indonesian Center for Volcanology and Geological Hazard Mitigation, this volcano has been at the third-highest alert level out of four since 2011, indicating activity above normal levels and advising climbers and villagers to stay more than 3 kilometers away from the summit to avoid disasters.
Mount Marapi is known for its sudden, unpredictable eruptions due to its shallow eruption sources located near the summit. Its eruptions are not caused by deep magma movements, which would generate seismic tremors recorded on monitoring equipment.
This is one of over 120 active volcanoes in Indonesia. The country is prone to seismic activity due to its location on the “Ring of Fire” of the Pacific Ocean—a volcanic arc and fault line surrounding the Pacific Ocean.
