Advances in our understanding of pyroclastic current behavior from the 1980 eruption sequence of Mount St. Helens volcano (Washington), USA

Advances in our understanding of pyroclastic current behavior from the 1980 eruption sequence of Mount St. Helens volcano (Washington), USA Brand B. D. auteur aut IRD Pollock N. auteur aut IRD Vallance J. W. auteur aut IRD Ongaro T. E. auteur aut IRD Roche Olivier auteur aut IRD Trolese M. auteur aut IRD Giordano G. auteur aut IRD Marshall A. A. auteur aut IRD Criswell C. W. auteur aut IRD text journalArticle eng text/pdf reformatted digital access This review summarizes what the volcanology community has learned thus far from studying the deposits of pyroclastic currents (PCs) from the 1980 eruption sequence at Mount St. Helens. The review includes mass flow events during the May 18 eruption, including the lateral blast, the afternoon column collapse and boil-over PC activity, and some aspects of the debris avalanche. We also include a summary of PCs generated in the smaller eruptions following the climactic May 18 event. Our objective is to summarize the state of our understanding of PC transport and emplacement mechanisms from the combination of field and laboratory observations, granular flow experiments, and numerical modeling techniques. Specifically, we couple deposit characteristics, experiments, and numerical modeling techniques to critically address the problems of (1) constraining conditions in the flow boundary zone at the time of deposition; (2) the influence of substrate roughness and topography on PC behavior; (3) the prevalence, causes, and consequences of substrate erosion by PCs; and (4) the reconstruction of PC transportation and sedimentation processes from a combination of geophysical and sedimentological observations. We conclude by providing opportunities for future research as our field, experimental, and numerical research techniques advance. specialized Mount St Helens Blast Pyroclastic current Pyroclastic density current Flow boundary zone ETATS UNIS 064 066 Bulletin of Volcanology 85 4 24 [33 p.] 2023 0258-8900 https://www.documentation.ird.fr/hor/fdi:010087524 10.1007/s00445-022-01617-w 0258-8900 [F B010087524] https://www.documentation.ird.fr/hor/fdi:010087524 https://horizon.documentation.ird.fr/exl-doc/pleins_textes/2023-05/010087524.pdf IRD - Base Horizon / Pleins textes 2023-05-12 2025-02-24 fdi:010087524 fre