Permeability control on magma fragmentation

Research Article| May 01, 2008 Permeability control on magma fragmentation Sebastian Mueller; Sebastian Mueller 1Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany, and Department of Earth Sciences, University of Bristol, Will Memorial Building, Queens Road, Bristol BS81RJ, UK Search for other works by this author on: GSW Google Scholar Bettina Scheu; Bettina Scheu 2Earthquake Research Institute, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, 113-023 Tokyo, Japan Search for other works by this author on: GSW Google Scholar Oliver Spieler; Oliver Spieler 3Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany Search for other works by this author on: GSW Google Scholar Donald B. Dingwell Donald B. Dingwell 3Earth and Environmental Sciences, University of Munich, Theresienstrasse 41, 80333 Munich, Germany Search for other works by this author on: GSW Google Scholar Geology (2008) 36 (5): 399–402. https://doi.org/10.1130/G24605A.1 Article history received: 13 Nov 2007 rev-recd: 26 Jan 2008 accepted: 29 Jan 2008 first online: 02 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Sebastian Mueller, Bettina Scheu, Oliver Spieler, Donald B. Dingwell; Permeability control on magma fragmentation. Geology 2008;; 36 (5): 399–402. doi: https://doi.org/10.1130/G24605A.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 Fragmentation of porous magma that is subject to gas overpressure is considered to be a crucial process in the generation of explosive volcanic eruptions. A decompressive event (e.g., rapid magma ascent, landslide, dome collapse) disrupts the stress equilibrium between the gas phase and the surrounding melt. When the gas in the pores is exposed to a pressure gradient, it may either fragment the surrounding magma or escape from the magma along an existing pathway of cracks and interconnected bubbles. Therefore, magma permeability can be a decisive parameter in determining if an eruption experiences fragmentation (i.e., whether it is explosive or effusive, or exhibits a temporal transition between the two eruptive styles). Despite the central role that gas permeability may play in the fragmentation of volcanic rocks, previous studies have not experimentally verified or quantified this influence. Based on a comprehensive database of combined permeability and fragmentation experiments, we show that high permeability substantially increases the overpressure required to fragment porous volcanic rocks. Our results allow us to deduce a fragmentation criterion that incorporates gas permeability as well as porosity and internal overpressure. This criterion implies that the energy required for fragmentation is less dependent on the actual pore geometry than on the way the void space is interconnected and, thus, on the contribution of permeable gas flow to decompression. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.