Harris A. auteur aut IRD Mannini S. auteur aut IRD Calabro L. auteur aut IRD Calvari S. auteur aut IRD Gurioli L. auteur aut IRD Chevrel Magdalena Oryaelle auteur aut IRD Favalli M. auteur aut IRD Villeneuve N. auteur aut IRD text journalArticle eng text/pdf born digital access Forest destruction by 'a'(a) over bar lava flow is common. However, mechanical and thermal interactions between the invading lava and the invaded forest are poorly constrained. We complete mapping, thermal image and sample analyses of a channel-fed 'a'(a) over bar lava flow system that invaded forest on the NE flank of Mt. Etna (Italy) in 2002. These lava flows destroyed 231,000 trees, only 2% of which are still visible as felled trunks on the levees or at the channel-levee contact. The remaining 98% were first felled by the flow front, with the trunks then buried by the flow. Rare tree molds can be found at the rubble levee base where trees were buried by avalanching hot breccia and then burnt through, with a time scale for total combustion being a few days. Protruding trunks fell away from the flow, if felled by blocks avalanching down the levee flank, or became aligned with the flow if falling onto the moving stream. Estimated cooling rates (0.1-5.5 degrees C km(-1)) are normal for well-insulated 'a'(a) over bar flow, suggesting no thermal interaction. We find the highest phenocryst concentrations (of 50-60%, above an expected value of 30-40%) in low velocity (<0.5 m s(-1)) locations. These low velocity zones are also characterized by high trunk concentrations. Thus, the common factor behind crystal and trunk deposition is velocity. That is, when the lava slows down, crystal settling occurs and trunks are preferentially deposited. Thus, although we find no thermal or textural effects due to the presence of the forest, we do find mechanical and environmental interactions where the trees are consumed to become part of the flow. specialized Channelized 'a' (a)over-bar lava flow Forest interaction Tree molds Cooling rates Phenocrysts ITALIE 066 082 064 020 429 107621 [13 ] 2022 0377-0273 https://www.documentation.ird.fr/hor/fdi:010085890 10.1016/j.jvolgeores.2022.107621 0377-0273 [F B010085890] https://www.documentation.ird.fr/hor/fdi:010085890 https://www.documentation.ird.fr/intranet/publi/2022-09/010085890.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2022-09-28 2025-02-24 fdi:010085890 fre