Results 121 to 130 of about 865,890 (160)

Pyroclastic Flow Deposits

1984
Pyroclastic flows are volcanically produced hot, gaseous, particulate density currents. Their deposits offer unparalleled opportunities to estimate minimum volumes of near-surface magma chambers as well as vertical chemical, mineralogical, and thus temperature and pressure distributions within the magma columns immediately prior to eruption.
Richard V. Fisher, Hans-Ulrich Schmincke
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CLASSIFICATION OF PYROCLASTIC FLOWS

International Geology Review, 1961
Pyroclastic 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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Fluidization in Pyroclastic Flow

1998
Engineering Foundation ...
MARZOCCHELLA, ANTONIO, SALATINO, PIERO, DI PASTENA V., LIRER L.   +3 more
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High performance computing simulations of pyroclastic flows

Computer Physics Communications, 2005
Explosive 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, Tomaso Esposti Ongaro, Giovanni Erbacci, Augusto Neri, Giovanni Macedonio   +4 more
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Violence in Pyroclastic Flow Eruptions

1981
Three 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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Factors governing the flow lineation of a large-scale pyroclastic flow — An example in the ata pyroclastic flow deposit, Japan

Bulletin Volcanologique, 1983
Schmincke andSwanson (1967) explained laminar flowage structures as indicators for flow direction of pyroclastic flows that show a radial flow pattern away from the source. Several other authors have reported similar examples, but the influence of pre-flow topographic relief has not been analyzed.
K. Suzuki, T. Ui
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In situ production of ash in pyroclastic flows

Journal of Geophysical Research: Solid Earth, 2008
Abrasion 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, 1987
Stratified 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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Emplacement of pyroclastic flows: A review

1979
Subaerial 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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Subaqueous pyroclastic flows: their development and their deposits

Geological Society, London, Special Publications, 1984
Summary 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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