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CLASSIFICATION OF PYROCLASTIC FLOWS
International Geology Review, 1961Pyroclastic flow is defined as the flow of high-temperature, essential, fragmental materials. This is synonymous with the nuee ardente in the broad sense. Three modes of emplacement of high-temperature, essential, solid (or liquid) materials after the ejection from the crater may be recognized: 1) Projection of fragments from the crater by explosive ...
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High performance computing simulations of pyroclastic flows
Computer Physics Communications, 2005Explosive volcanic eruptions are certainly one of the most complex phenomena occurring in nature. In addition, the occurrence of pyroclastic flows, i.e. of high-velocity and high-temperature ground-hugging flows produced by the collapse of volcanic column, represent a very hazardous phenomenon for the nearby urbanized areas.
Carlo Cavazzoni +4 more
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SMOOTHED PARTICLE SIMULATIONS OF THE PYROCLASTIC FLOW
International Journal of Modern Physics B, 1993We apply the Smoothed Particle Hydrodynamics (SPH) to the three-dimensional simulation of pyroclastic flow over the terrain in Unzen area. The actual flow was observed in June 1991. The comparison of the simulation with the observation tells us the proper parameter sets for this kind of particle simulation.
MIKIO NAGASAWA, KUNIO KUWAHARA
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Violence in Pyroclastic Flow Eruptions
1981Three parameters, magnitude, intensity, and violence, can be used to characterise pyroclastic flow eruptions. Violence reflects the vigour with which a pyroclastic flow is emplaced. It is described quantitatively by the height of hills climbed by the flow (yielding flow-velocity estimates), the overall morphology of the deposit and by the proportion of
C. J. N. Wilson, G. P. L. Walker
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In situ production of ash in pyroclastic flows
Journal of Geophysical Research: Solid Earth, 2008Abrasion and comminution of pumice clasts during the propagation of pyroclastic flows have long been recognized as a potential source for the enhanced production of volcanic ash, however, their relative importance has eluded quantification. The amount of ash produced in situ can potentially affect runout distance, deposit sorting, the volume of ash ...
J. Dufek, M. Manga
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Stratified flow in pyroclastic surges
Bulletin of Volcanology, 1987Stratified flow theory is applied to pyroclatic surges in an effort to gain insight into transport dynamics during explosive eruptions. Particle transport is assumed to be by turbulent suspension, and calculations contained herein show that this is likely for many cases including the 18 May 1980 blast at mount St. Helens.
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Subaqueous pyroclastic flows: their development and their deposits
Geological Society, London, Special Publications, 1984Summary Subaqueous pyroclastic flows are generated by eruptions in shallow water or close to a shore. Their flow mechanism is similar to that of their subaerial counterparts, except that they incorporate steam and not air. Near the source area, their deposits are non-sorted and resemble subaerial flow deposits.
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Mechanism of deposition from pyroclastic flows
American Journal of Science, 1966Drag resistance developed between a pyroclastic flow and the ground results in a transitional zone of low velocity between the maximum velocity of the flow and the stationary ground. Fragments of all sizes within the turbulent flow travel irregular paths and therefore enter the reduced velocity zone at random and are deposited together irrespective of ...
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Emplacement of pyroclastic flows: A review
1979Subaerial pyroclastic deposits are of three genetic types: (1) fall, (2) surge, and (3) flow. Although pyroclastic flows include a wide range of volume magnitudes, only small-scale eruptions have been observed. Flows are composed of a dense, basal avalanche and an overriding cloud of entrained particles that rise by convective buoyancy.
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