@article{fdi:010053832,
  title = {{S}uitability of simple rheological laws for the numerical simulation of dense pyroclastic flows and long-runout volcanic avalanches},
  author = {{K}elfoun, {K}arim},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he rheology of volcanic rock avalanches and dense pyroclastic flows is complex, and it is difficult at present to constrain the physics of their processes. {T}he problem lies in defining the most suitable parameters for simulating the behavior of these natural flows. {E}xisting models are often based on the {C}oulomb rheology, sometimes with a velocity-dependent stress (e.g., {V}oellmy), but other laws have also been used. {H}ere {I} explore the characteristics of flows, and their deposits, obtained on simplified topographies by varying source conditions and rheology. {T}he {C}oulomb rheology, irrespective of whether there is a velocity-dependent stress, forms cone-shaped deposits that do not resemble those of natural long-runout events. {A} purely viscous or a purely turbulent flow can achieve realistic velocities and thicknesses but cannot form a deposit on slopes. {T}he plastic rheology, with (e.g., {B}ingham) or without a velocity-dependent stress, is more suitable for the simulation of dense pyroclastic flows and long-runout volcanic avalanches. {W}ith this rheology, numerical flows form by pulses, which are often observed during natural flow emplacement. {T}he flows exhibit realistic velocities and deposits of realistic thicknesses. {T}he plastic rheology is also able to generate the frontal lobes and lateral levees which are commonly observed in the field. {W}ith the plastic rheology, levee formation occurs at the flow front due to a divergence of the driving stresses at the edges. {O}nce formed, the levees then channel the remaining flow mass. {T}he results should help future modelers of volcanic flows with their choice of which mechanical law corresponds best to the event they are studying.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch. {S}olid {E}arth},
  volume = {116},
  numero = {},
  pages = {{B}08209},
  ISSN = {0148-0227},
  year = {2011},
  DOI = {10.1029/2010jb007622},
  URL = {https://www.documentation.ird.fr/hor/fdi:010053832},
}