@article{fdi:010062265,
  title = {{A}utofluidization of pyroclastic flows propagating on rough substrates as shown by laboratory experiments},
  author = {{C}hedeville, {C}. and {R}oche, {O}livier},
  editor = {},
  language = {{ENG}},
  abstract = {{T}his study investigates the influence of the substrate surface roughness on the emplacement mechanisms of pyroclastic flows. {W}e carried out laboratory experiments on gravitational flows generated from the release of initially fluidized or nonfluidized columns of fine particles (diameter d = 0.08 mm) in a horizontal channel. {T}he roughness of the channel base was uniform in each experiment, created by gluing particles of diameter d(0) = 0.08 to 6mm to the base. {O}ther things being equal, the flow runout distance increased with the channel base roughness (d(0)) to a maximum of about twice that of flows on a smooth substrate when d(0) = 1.5-3 mm, before decreasing moderately at higher roughness values of d(0) = 6 mm. {L}ong runout originated mainly during the late stages of emplacement as flow deceleration was strongly reduced at high substrate roughness. {T}his was caused by (partial) autofluidization due to an upward air flux escaping from the substrate interstices in which flow particles settled. {A}utofluidization was evidenced by high pore fluid pressure measurements at the base of initially nonfluidized flows and also by reduced flow runout when the interstices were initially partially filled so that less air was available. {F}urthermore, the runout distance of flows of large particles (d = 0.35 mm), which could not be fluidized by the ascending air flux, was independent of the substrate roughness. {T}his study suggests that autofluidization caused by air escape from the interstices of a rough substrate is one important mechanism to explain the common long runout distance of pyroclastic flows even on subhorizontal topographies.},
  keywords = {},
  booktitle = {},
  journal = {{J}ournal of {G}eophysical {R}esearch.{S}olid {E}arth},
  volume = {119},
  numero = {3},
  pages = {1764--1776},
  ISSN = {2169-9313},
  year = {2014},
  DOI = {10.1002/2013jb010554},
  URL = {https://www.documentation.ird.fr/hor/fdi:010062265},
}