lahar
Học thuậtThân thiện
Definition
Noun: A lahar is a destructive, fast-moving flow of water, volcanic ash, rock fragments, and mud down the slopes of a volcano. It behaves like a fluid avalanche and is often triggered by heavy rainfall on loose volcanic deposits or by volcanic activity melting snow and ice.
Usage
The word lahar is used to describe a specific and dangerous geological phenomenon associated with volcanoes. It is a technical term common in geology, volcanology, and disaster reporting.
Examples
- The eruption melted the glacier, generating a massive lahar that buried villages in its path.
- Scientists monitor rainfall near the volcano to warn of potential lahar threats.
- The valley's topography shows evidence of ancient lahars from previous eruptions.
Advanced Usage
- Lahars can travel many kilometers from their source volcano, following river valleys and causing devastation far from the eruption site.
- Unlike lava flows, lahars can occur even when a volcano is not actively erupting, if heavy rain mobilizes unstable ash deposits.
Variants and Related Words
- Debris flow: A more general term for a fast-moving slurry of mud, water, and rock; a lahar is a specific type of volcanic debris flow.
- Mudflow: A flow of water and fine-grained sediment; a lahar often contains coarser material like boulders.
Synonyms
- Volcanic mudflow
- Debris avalanche (in a volcanic context)
Related Phrases/Idioms
There are no common idioms or phrasal verbs using the specific term lahar. It is used literally to describe the geological event.
Noun
- an avalanche of volcanic water and mud down the slopes of a volcano