Definitions for "Pyroclastic flow"
Flowage of a mixture of hot gases and unsorted pyroclastic material that can move at a maximum speed of 100 miles an hour.
A hot mixture of volcanic rock fragments (pyroclasts) and gases that, driven by gravity, flows down a volcano's flank at high speed
A glowing cloud of volcanic ash, fragments of volcanic rock, and gases that moves rapidly downhill away from the eruptive center during a volcanic eruption.