Pyroclastic flow — Pyroclastic flows sweep down the flanks of Mayon Volcano, Philippines, in 1984 … Wikipedia
pyroclastic flow — ▪ volcanism in a volcanic eruption, a fluidized mixture of hot rock fragments, hot gases, and entrapped air that moves at high speed in thick, gray to black, turbulent clouds that hug the ground. The temperature of the volcanic gases can… … Universalium
pyroclastic flow — ALASKA VOLCANO OBSERVATORY GLOSSARY A dense, hot, chaotic avalanche of rock fragments, gas, and ash that travels rapidly away from an explosive eruption column, down the flanks of the volcano (synonymous with ash flow ). Pyroclastic flows move at … Glossary of volcanic terms
pyroclastic flow deposit — GLOSSARY OF VOLCANIC TERMS Pyroclastic (volcaniclastic) deposits that are left by pyroclastic flows (Cas and Wright, 1987, p. 96). The deposits are usually topographically controlled (infilling valleys and topographic depressions), massive, and… … Glossary of volcanic terms
pyroclastic flow — noun /ˈpaɪ.ɹə.klæst.ɪk ˌfləʊ/ A flow of volcanic ash, dust, rocks and debris that cascades down the slope of a volcano during an eruption. Pyroclastic flows are very dangerous, reaching speeds greater than 60 miles per hour and temperatures in… … Wiktionary
pyroclastic flow — … Useful english dictionary
Pyroclastic rock — Pyroclastic rocks or pyroclastics (derived from the Greek πῦρ , meaning fire, and κλαστός , meaning broken) are clastic rocks composed solely or primarily of volcanic materials. Where the volcanic material has been transported and reworked… … Wikipedia
Pyroclastic surge — A pyroclastic surge is a fluidized mass of turbulent gas and rock fragments which is ejected during some volcanic eruptions. It is similar to a pyroclastic flow but contains a much higher proportion of gas to rock, which makes it more turbulent… … Wikipedia
Pyroclastic fall — A pyroclastic fall is a uniform deposit of material which has been ejected from an eruption or plume such as an ash fall or tuff. Pyroclastic flows occur relatively spontaneously in the geological time scale and are great indicators of time.… … Wikipedia
pyroclastic surge — A low density, dilute, turbulent pyroclastic flow, usually very hot, composed of a generally unsorted mixture of gases and comparatively low concentrations of pyroclastic particles (ash, pumice, and dense rock fragments) that travels across… … Glossary of landform and geologic terms
