pyroclastic density current
English
Noun
pyroclastic density current (plural pyroclastic density currents)
- a pyroclastic flow; a gas-rich, hot, dense, ground-hugging torrent of ash, lapilli, and volcanic blocks that results from the gravitational collapse of a volcanic eruption column, associated with explosive plinian and ultraplinian volcanic eruptions, and which produces a type of volcaniclastic deposit called an ash-flow tuff or an ignimbrite.