Fast-moving current of hot gas and volcanic matter that moves away from a volcano
Pyroclastic flows sweep down the flanks of Mayon Volcano, Philippines, in 1984
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud)[1] 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 average speeds of 100 km/h (30 m/s; 60 mph) but is capable of reaching speeds up to 700 km/h (190 m/s; 430 mph).[2] The gases and tephra can reach temperatures of about 1,000 °C (1,800 °F).
Pyroclastic flows are the most deadly of all volcanic hazards[3] and are produced as a result of certain explosive eruptions; they normally touch the ground and hurtle downhill or spread laterally under gravity. Their speed depends upon the density of the current, the volcanic output rate, and the gradient of the slope.
^Branney M.J. & Kokelaar, B.P. 2002, Pyroclastic Density Currents and the Sedimentation of Ignimbrites. Geological Society of London Memoir 27, 143pp.
^"MSH Pyroclastic flow [USGS]". pubs.usgs.gov.
^Auker, Melanie Rose; Sparks, Robert Stephen John; Siebert, Lee; Crosweller, Helen Sian; Ewert, John (2013-02-14). "A statistical analysis of the global historical volcanic fatalities record". Journal of Applied Volcanology. 2 (1): 2. Bibcode:2013JApV....2....2A. doi:10.1186/2191-5040-2-2. ISSN 2191-5040. S2CID 44008872.
A pyroclasticflow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively...
active from 1990 to 1995, and a large eruption in 1991 generated a pyroclasticflow that killed 43 people, including three volcanologists. Its highest...
that is ejected during some volcanic eruptions. It is similar to a pyroclasticflow but it has a lower density or contains a much higher ratio of gas to...
the Sunda Strait and places on the Sumatran coast were affected by pyroclasticflows from the volcano. Material shot out of the volcano at 2,575 kilometres...
topography-draping pyroclastic fall layers, and by pyroclastic density currents (PDCs) (including pyroclasticflows and pyroclastic surges), from which...
ejecta from a volcanic vent Pyroclastic fall, a uniform deposit of material ejected from a volcanic eruption Pyroclasticflow, a fast-moving current of...
atmosphere. This cloud may subsequently collapse, creating a fast-moving pyroclasticflow of hot volcanic matter. Viscous magmas cool beneath the surface before...
of the rapidly approaching ash cloud. Before he was engulfed by the pyroclasticflow, he rewound the film back into its case, put his camera in his backpack...
Stratocones are large cone-shaped volcanoes made up of lava flows, explosively erupted pyroclastic rocks, and igneous intrusives that are typically centered...
second phase Tsumaya pyroclasticflow deposit which is wholly confined within the pre-Aira basin. The Tsumaya pyroclasticflow buried the pre-Aira topography...
explosive eruption in January 1929 also included an apparent pyroclasticflow and a lava flow. The last major eruption of Calbuco, in 1961, sent ash columns...
known to occur in pyroclasticflows, which will incinerate everything flammable in their path, and thick layers of hot pyroclasticflow deposits can be...
June 1991) were French volcanologists and filmmakers who died in a pyroclasticflow on Mount Unzen, Nagasaki, Japan, on 3 June 1991. The Kraffts became...
gas, allowing it to spread. Pyroclasticflows can often climb over obstacles, and devastate human life. Pyroclasticflows are a common feature at explosive...
displayed, including weak phreatomagmatism, Plinian eruptions, and a huge pyroclasticflow. Rhyolitic lava domes were extruded some years or decades later, forming...
centred about the Qualibou depression, contains pyroclasticflow deposits, lava flows, domes, block and ash flow deposits, and explosion craters. This depression's...
outcrops, lava flows with a thickness of 2–10 metres (6 ft 7 in – 32 ft 10 in) appear to be widespread on Mount Takahe, while pyroclastic rocks such as...
caused by pyroclasticflows and lahars, deadly hazards that often accompany explosive eruptions of subduction-zone stratovolcanoes. Pyroclasticflows are swift...
the nearby area through lava flows, pyroclasticflows, lahars (volcanically induced mudslides, landslides, and debris flows), ash, avalanches, and floods...
of the remote cameras were ever found. Blackburn was killed when a pyroclasticflow enveloped the area where he was camped out. His car was found four...
from the mountaintop, and several eruptions have caused fatalities. A pyroclasticflow from a large explosion killed 27 people on 22 November 1994, mostly...
violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically...
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