noun
volcanic sector collapse; debris avalanche
Geological term for a large-scale collapse of a volcanic edifice, often producing a debris avalanche. Used in technical and disaster-prevention contexts.
山体崩壊によって大規模な岩屑なだれが発生した。
A large-scale debris avalanche was triggered by the sector collapse.
この火山は過去に何度も山体崩壊を起こしている。
This volcano has experienced sector collapses many times in the past.
Compound of 山体 (さんたい, 'mountain body') and 崩壊 (ほうかい, 'collapse'). The term is used in volcanology and geology.