HR: 13:40h
AN: V53E-01 INVITED    [Abstracts]
TI: Volcanic halogen emissions: sources and consequences
AU: * Mather, T A
EM: tamsinm@earth.ox.ac.uk
AF: Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom
AU: Pyle, D M
EM: davidp@earth.ox.ac.uk
AF: Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom
AU: Aiuppa, A
EM: aiuppa@unipa.it
AF: Dipartimento CFTA, Università  di Palermo, Via archirafi 36, Palermo, 90123, Italy
AU: Millard, G A
EM: gmil05@esc.cam.ac.uk
AF: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom
AU: Rose, W I
EM: raman@mtu.edu
AF: Geological Engineering and Sciences, Michigan Technological University, Houghton, MI 49931, United States
AU: Martin, R S
EM: rsm45@cam.ac.uk
AF: Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom
AB: We present an overview of our recent work concerning the sources of halogens in volcanic emissions; how inert hydrogen halides in volcanic gases become activated into environmentally reactive species, and some of the potential consequences of these species. Previous studies have suggested that the Cl in volcanic emissions is the result of efficient recycling of Cl taken down with the subducting slab. We will present new results from Nicaragua for volcanic Br and I emissions, as well as Cl. Our results are consistent with a subduction source for I. In general, the volcanic samples are more enriched in Cl than many other Earth system reservoirs. We will discuss some of the questions that this raises, and review the scale of global volcanic halogen emissions. Once emitted from the magma, volcanic halogen species may cause localised ozone depletion both in the troposphere (following activation by high-temperature mixing with atmospheric oxygen) and the stratosphere (due to their interactions with other volcanic plume components as shown in the recent studies of the Hekla plume in 2000).
DE: 8409 Atmospheric effects (0370)
DE: 8430 Volcanic gases
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2007 Fall Meeting