Pre-eruptive reheating during magma mixing at Quizapu volcano and the implications for the explosiveness of silicic arc volcanoes

Research Article| October 01, 2010 Pre-eruptive reheating during magma mixing at Quizapu volcano and the implications for the explosiveness of silicic arc volcanoes Philipp Ruprecht; Philipp Ruprecht 1Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, Washington 98195, USA2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Box 1000, Palisades, New York 10964, USA Search for other works by this author on: GSW Google Scholar Olivier Bachmann Olivier Bachmann 1Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, Washington 98195, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Philipp Ruprecht 1Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, Washington 98195, USA2Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Box 1000, Palisades, New York 10964, USA Olivier Bachmann 1Department of Earth and Space Sciences, University of Washington, Box 351310, Seattle, Washington 98195, USA Publisher: Geological Society of America Received: 09 Feb 2010 Revision Received: 11 May 2010 Accepted: 21 May 2010 First Online: 09 Mar 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2010 Geological Society of America Geology (2010) 38 (10): 919–922. https://doi.org/10.1130/G31110.1 Article history Received: 09 Feb 2010 Revision Received: 11 May 2010 Accepted: 21 May 2010 First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Philipp Ruprecht, Olivier Bachmann; Pre-eruptive reheating during magma mixing at Quizapu volcano and the implications for the explosiveness of silicic arc volcanoes. Geology 2010;; 38 (10): 919–922. doi: https://doi.org/10.1130/G31110.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Effusive-explosive transitions are observed in volcanoes erupting water-rich magmas that lack mineralogical evidence of degassing, suggesting that gas loss occurred rapidly and ascent was fast despite the high viscosity of rhyodacitic to rhyolitic melts. Here, we show that pre-eruptive heating of water-rich, silicic magma by mixing with hot recharge in subvolcanic chambers controls the effusive-explosive transition. Volcán Quizapu (Chile) emitted a 5 km3 mingled dacite-andesite lava flow in A.D. 1846–1847 that was ∼130 °C hotter than the 5 km3 of the same dacite that lead to a Plinian eruption in A.D. 1932. We explain the suppression of explosive fragmentation in the 1846–1847 lavas by enhanced syneruptive magma degassing as a consequence of late reheating following mixing with andesite recharge. Higher magma temperatures led to the transitioning into effusive eruptive behavior by significantly accelerating volatile diffusion and lowering melt viscosity, which facilitated bubble nucleation, growth, and coalescence, while also inhibiting brittle fragmentation. Thus, recharge by mafic magmas in subvolcanic magma chambers may reduce the risk of explosive eruptions in cases where heat can be efficiently transferred to cold, volatile-rich silicic magmas. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.