landslide dam
A natural dam formed when a landslide blocks a river or valley, often creating a temporary lake and posing a flood risk if it collapses.
地震でできた土砂ダムが決壊する恐れがある。
There is a risk that the landslide dam formed by the earthquake will collapse.
土砂ダムの上流側には水がたまり、湖のようになっていた。
Water had accumulated upstream of the landslide dam, forming a lake-like body.
Compound of 土砂 (dirt and sand, debris) and ダム (dam, from English). The term is used in geology and disaster prevention contexts.