Pyroclastic flow

Rocks from the Bishop tuff, uncompressed with pumice (on left); compressed with fiamme (on right).

A scientist examines pumice blocks at the edge of a pyroclastic flow deposit from Mount St. Helens

A pyroclastic flow (also known scientifically as a pyroclastic density current) is a fast-moving current of hot gas and rock (collectively known as tephra), which reaches speeds moving away from a volcano of up to 700 km/h (450 mph). The gas can reach temperatures of about 1,000 °C (1,830 °F). Pyroclastic flows normally hug the ground and travel downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. They are a common and devastating result of certain explosive volcanic eruptions.

单词	Nuee Ardente
释义	Nuee Ardente 英语百科 Pyroclastic flow A pyroclastic flow (also known scientifically as a pyroclastic density current) is a fast-moving current of hot gas and rock (collectively known as tephra), which reaches speeds moving away from a volcano of up to 700 km/h (450 mph). The gas can reach temperatures of about 1,000 °C (1,830 °F). Pyroclastic flows normally hug the ground and travel downhill, or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope. They are a common and devastating result of certain explosive volcanic eruptions.
随便看	mmic switch的意思 mmic synthesizer的意思 mmic transmitter的意思 MMID的意思 MMIF的意思 MM intensity scale的意思 mm. intercostales externi的意思 mm. intercostales interni的意思 Mm. intercostales lumbales的意思 Mm. intercostotransversarii ventrales的意思 mm. interossei dorsales的意思 mm. interossei plantares的意思 mm. interossei volares的意思 Mm. interspinales cervicis的意思 Mm. intertransversarii cervicales的意思 mm. intertransversarii poteriores的意思 mminus的意思 MMIO的意思 MMIPS的意思 MMIRA的意思 MMI的意思 MM isoenzyme of creatine kinase的意思 MMIT的意思 mmite disease的意思 M.Mizuno et W.L.Zhao的意思

Nuee Ardente

Pyroclastic flow