Results 111 to 120 of about 2,889,255 (157)

Deposits of Pyroclastic Density Currents

2015
Richard J Brown, Graham D. M. Andrews
exaly   +2 more sources

Erosional characteristics and behavior of large pyroclastic density currents

Geology, 2012
Factors influencing the erosive behavior of large pyroclastic density currents (PDCs), both mainly massive and thinly stratified, are not well understood. To investigate the parameters influencing the erosive behavior of PDCs produced during the flowing phase of large, caldera-forming Plinian (Campanian Ignimbrite) and phreatoplinian (Neapolitan Yellow
SCARPATI, CLAUDIO, Perrotta A.
openaire   +4 more sources

Generation of Overspill Pyroclastic Density Currents in Sinuous Channels

Journal of Geophysical Research: Solid Earth, 2021
AbstractDue to their mobility, high velocities, and common occurrence, small‐volume pyroclastic density currents (PDCs) represent a major hazard around volcanoes. Small‐volume events are particularly sensitive to topography and channelization into drainage basins. Understanding the flow transition initiated by avulsion or overspill from valley confined
A. Kubo Hutchison, J. Dufek
openaire   +1 more source

Pyroclastic density currents

Geological Society, London, Special Publications, 1998
Abstract High-speed, gravity-driven flows of hot particles and gas are a common and highly destructive product of explosive volcanism. They range widely in nature from expanded, turbulent suspension currents formed by lateral blasts or by the fountaining of vertical eruption columns, to highly concentrated granular avalanches ...
openaire   +1 more source

The Fluid Mechanics of Pyroclastic Density Currents

Annual Review of Fluid Mechanics, 2016
Pyroclastic density currents are generated in explosive volcanic eruptions when gas and particle mixtures remain denser than the surrounding atmosphere. These mobile currents have a diversity of flow regimes, from energetic granular flows to turbulent suspensions. Given their hazardous nature, much of our understanding of the internal dynamics of these
openaire   +1 more source

Revaluating the Vertical Velocity and Density Structure of Dilute Pyroclastic Density Currents

2023
Dilute pyroclastic density currents (dilute PDCs) are frequent and hazardous volcanic phenomena. Better mitigating against PDC hazards requires understanding of the vertical velocity and density structures inside flows and how these are modified during flow runout, particle sedimentation, air entrainment and buoyancy reversal.
Uhle, D., Ardo, J., Lube, G., Jones, J.
openaire   +2 more sources

Effects of flow density on the dynamics of dilute pyroclastic density currents

Journal of Volcanology and Geothermal Research, 2004
Abstract Dilute turbulent pyroclastic density currents may have densities as large as 10–100 kg m −3 . Laboratory experiments using dense gases show that for such currents, the speed of the head of the current depends on the density difference between the current and the surrounding air in a complex way.
Sarah E. Nield, Andrew W. Woods
openaire   +1 more source

Density Stratification and Buoyancy Evolution in Pyroclastic Density Currents

Journal of Geophysical Research: Solid Earth
AbstractPyroclastic density currents (PDCs) are density‐stratified along their vertical axis, with the near‐bed portion being denser than the upper portion, resulting from particle settling and ambient air entrainment at current margins. Whereas vertical density stratification likely influences mixing, sedimentation, and buoyancy of PDCs, many depth ...
Sean B. O’Donnell, Blair A. Johnson, Eric C. P. Breard, James L. Buttles, James E. Gardner, David Mohrig, Josef Dufek   +6 more
openaire   +1 more source

Pyroclastic Density Currents at Volcán de Colima

2019
In the last ~500 years, Volcan de Colima has generated numerous small-volume pyroclastic density currents (PDCs) that have been associated with dome emplacement, either by a partial collapse or by their explosive destruction. Large PDCs were generated by eruption column collapse in 1690, 1818, and 1913.
R. Saucedo, J. L. Macías, J. C. Gavilanes-Ruiz, M. I. Bursik, V. Vargas-Gutiérrez   +4 more
openaire   +1 more source

Generation of air lubrication within pyroclastic density currents

Nature Geoscience, 2019
Pyroclastic density currents are highly dangerous ground-hugging currents from volcanoes that cause >50% of volcanic fatalities globally. These hot mixtures of volcanic particles and gas exhibit remarkable fluidity, which allows them to transport thousands to millions of tonnes of volcanic material across the Earth’s surface over tens to hundreds of ...
Gert Lube, Eric C. P. Breard, Jim Jones, Luke Fullard, Josef Dufek, Shane J. Cronin, Ting Wang   +6 more
openaire   +1 more source