Gueugneau V. auteur aut IRD Kelfoun K. auteur aut IRD Roche Olivier auteur aut IRD Chupin L. auteur aut IRD text journalArticle eng text/pdf born digital access Pyroclastic flows are mixtures of volcanic gases and particles that can be very hazardous owing to their fluid-like behavior. One possible mechanism to explain this behavior is the reduction of particles friction due to the internal gas pore pressure. To verify this hypothesis, we present a numerical model of a granular flow with high initial pore pressure that decreases with time as the gas-particle mixture propagates. First, we validate the model by reproducing laboratory experiments. Then, the numerical code is applied to pyroclastic flows of Lascar volcano (1993 eruption, Chile). The simulation reproduces the runout and the morphological features of the deposits, with lateral levees, a central channel, and a lobate front. Our results support the hypothesis of the role of gas pore pressure in pyroclastic flows and explain both the fluid-like behavior of the flows and the formation of lateral levees. specialized 064 066 44 5 2194-2202 2017 0094-8276 https://www.documentation.ird.fr/hor/fdi:010069368 10.1002/2017gl072591 0094-8276 [F B010069368] https://www.documentation.ird.fr/hor/fdi:010069368 https://www.documentation.ird.fr/intranet/publi/2017/04/010069368.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-05-09 2023-07-11 fdi:010069368 fre