A pyroclastic flow from Mayon in the Philippines, seen on September 23, 1984. Pyroclastic flow synonyms, Pyroclastic flow pronunciation, Pyroclastic flow translation, English dictionary definition of Pyroclastic flow. A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at velocities of 100 km/h (62 mph) on average but is capable of reaching speeds up to 700 km/h (430 mph). In fact, this type of flow is sometimes known as a “pumice flow.” Heavy debris falls rapidly from the sky and flows down the flanks of the volcano, mostly as pumice. St. Helens, Skamania County, Washington August 7, 1980 n. pl. What does pyroclastic flow mean? Soufriere type. nuée ardente eruption of Mt. Information and translations of pyroclastic flow in the most comprehensive dictionary definitions resource on the web. These mixtures of ash, lava blebs and broiling gas … Composed chiefly of rock fragments or particles of volcanic origin, such as pumice, obsidian, or volcanic ash. Meaning of pyroclastic flow. pyroclastic synonyms, pyroclastic pronunciation, pyroclastic translation, English dictionary definition of pyroclastic. Pumice flow. adj. A pyroclastic flow with a mechanism that generates nuee ardente deposits of block and ash which are generated by dome collapse caused by a gas driven explosion. A pyroclastic flow (also known scientifically as a pyroclastic density current [1]) is a fast-moving current of superheated gas and rock (collectively known as tephra), which reaches speeds moving away from a volcano of up to 700 km/h (450 mph). Pyroclastic flows vary considerably in size and speed, but even relatively small flows that move less than 5 km (3 mi) from a volcano can destroy buildings, forests, and farmland. Define pyroclastic. Definition of pyroclastic flow in the Definitions.net dictionary. A pyroclastic flow with a mechanism involving the collapse of an eruption column. I've labeled the main parts of a pyroclastic, with the leading surge, main body and accompanying ash cloud. Pyroclastic flows are a very dangerous phenomenon that occur during some volcanic eruptions. Other pyroclastic flows result from the collapse of an eruption column, the vertical mass of debris and gas that jets above an explosive volcano vent. Pyroclastic flows are the signature fireworks of the most explosive kinds of volcanic eruptions. Pyroclastic flow, the fast-moving hot gases, ash, and cinders expelled from a volcano. The speed of these flows, as well as the extremely high … ‘The pyroclastic deposits mainly consist of block-and-ash, blast, tephra fallout and secondary pyroclastic flow deposits.’ ‘And they also say there's a potential danger from pyroclastic flows.’ ‘The pyroclastic deposits mainly consist of block-and-ash, blast, tephra fallout and secondary pyroclastic flow deposits.’ ‘And they also say there's a potential danger from pyroclastic flows.’ On the margins of pyroclastic flows, death and serious injury to people and animals may result from burns and inhalation of …