Title
Effects of Host-rock Fracturing on Elastic-deformation Source Models of Volcano Deflation
Author
Eoghan P. Holohan
UCD School of Earth Sciences, University College Dublin
Henriette Sudhaus
Section 2.1 - Physics of Earthquakes and Volcanoes, GFZ-German Research Centre for Geosciences
Thomas R. Walter
Section 2.1 - Physics of Earthquakes and Volcanoes, GFZ-German Research Centre for Geosciences
... show all
Abstract
Volcanoes commonly inflate or deflate during episodes of unrest or eruption. Continuum mechanics models that assume linear elastic deformation of the Earth’s crust are routinely used to invert the observed ground motions. The source(s) of deformation in such models are generally interpreted in terms of magma bodies or pathways, and thus form a basis for hazard assessment and mitigation. Using discontinuum mechanics models, we show how host-rock fracturing (i.e. non-elastic deformation) during drainage of a magma body can progressively change the shape and depth of an elastic-deformation source. We argue that this effect explains the marked spatio-temporal changes in source model attributes inferred for the March-April 2007 eruption of Piton de la Fournaise volcano, La Reunion. We find that pronounced deflation-related host-rock fracturing can: (1) yield inclined source model geometries for a horizontal magma body; (2) cause significant upward migration of an elastic-deformation source, leading to underestimation of the true magma body depth and potentially to a misinterpretation of ascending magma; and (3) at least partly explain underestimation by elastic–deformation sources of changes in sub-surface magma volume.
Keywords
GeophysicsNatural hazardsStructural geologyTectonicsVolcanology
Object type
Language
English [eng]
Persistent identifier
phaidra.univie.ac.at/o:912588
Appeared in
Title
Scientific Reports
Volume
7
Publication
Springer Nature
Version type
Date issued
2017
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Rights
Rights statement
© The Author(s) 2017
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