Large Lahar / Flash Flood Races Down Semeru Volcano’s Riverbed – Nov 7, 2025

At 13:45 local time on November 7, 2025, our Semeru Volcano webcams (Cam B and C) captured a powerful lahar (volcanic mudflow) or flash flood racing down the dry riverbed where workers often excavate black volcanic sand for construction use. This sudden surge of water and debris highlights the ever-present dangers around Indonesia’s most active volcano. Lahars are mixtures of water, volcanic ash, and rock fragments that can occur suddenly when heavy rainfall or crater activity remobilizes loose volcanic material. Even without an eruption, they can be deadly — capable of sweeping away anything in their path at high speed. Fortunately, no one was injured in this event. Mount Semeru (3,676 m), located in East Java, is Indonesia’s highest volcano and among its most frequently active, with ongoing eruptions and periodic ash emissions. 📍 Location: Semeru Volcano, East Java, Indonesia 🎥 Captured by: AfarTV 24/7 Livestream #Semeru #Volcano #Lahar #FlashFlood #Indonesia #VolcanicActivity #AfarTV #SemeruVolcano #NaturalDisaster #MountSemeru #VolcanoLive #EastJava #Eruption #VolcanoWatch #Geology