Pyroclastic materials are clouds of ash, vapor, and lava
fragments carried through the air. When this occurs during a volcanic eruption it
produces low-viscosity lava. Viscosity refers to the thickness of materials and
its resistance to flow. When pyroclastic materials sore through the air they
are very hot and they move rapidly because vapor provides its buoyancy. Due to
its general make-up, these materials are capable for destroying life and property
within their paths and can extend miles away from the volcano.
