Pyroclastic Flow 9
Pyroclastic Flow 9 : Natural Disaster. High density flow of solid volcanic fragments suspended in gas which flows down-slope from a volcanic vent (at speeds up to 200 kilometres per hour) which may also develop from partial collapse of a vertical eruption cone, subdivided according to fragment composition and nature of flowage into: ash flow, glowing avalanche, nuee ardente, pumice flow. See also: Lahar