title: Volcanology. A large magmatic sill complex beneath the Toba caldera.
abstract: An understanding of the formation of large magmatic reservoirs is a key issue for the evaluation of possible strong volcanic eruptions in the future. We estimated the size and level of maturity of one of the largest volcanic reservoirs, based on radial seismic anisotropy. We used ambient-noise seismic tomography below the Toba caldera (in northern Sumatra) to observe the anisotropy that we interpret as the expression of a fine-scale layering caused by the presence of many partially molten sills in the crust below 7 kilometers. This result demonstrates that the magmatic reservoirs of present (non-eroded) supervolcanoes can be formed as large sill complexes and supports the concept of the long-term incremental evolution of magma bodies that lead to the largest volcanic eruptions.
authors.affiliation: Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of Russian Academy of Sciences, Prospekt Koptyuga, 3, Novosibirsk, 630090 Russia. Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090, Russia. Institut de Physique du Globe de Paris, Sorbonne Paris Cité, CNRS (UMR 7154), 1 rue Jussieu, 75238 Paris, Cedex 5, France.
authors.forename: K
authors.initials: K
authors.lastname: Jaxybulatov
authors.affiliation: Institut de Physique du Globe de Paris, Sorbonne Paris Cité, CNRS (UMR 7154), 1 rue Jussieu, 75238 Paris, Cedex 5, France. nshapiro@ipgp.fr.
authors.forename: N M
authors.initials: NM
authors.lastname: Shapiro
authors.affiliation: Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of Russian Academy of Sciences, Prospekt Koptyuga, 3, Novosibirsk, 630090 Russia. Novosibirsk State University, 2, Pirogova Street, Novosibirsk 630090, Russia.
authors.forename: I
authors.initials: I
authors.lastname: Koulakov
authors.affiliation: Institut de Physique du Globe de Paris, Sorbonne Paris Cité, CNRS (UMR 7154), 1 rue Jussieu, 75238 Paris, Cedex 5, France.
authors.forename: A
authors.initials: A
authors.lastname: Mordret
authors.affiliation: Institut de Physique du Globe de Paris, Sorbonne Paris Cité, CNRS (UMR 7154), 1 rue Jussieu, 75238 Paris, Cedex 5, France.
authors.forename: M
authors.initials: M
authors.lastname: Landès
authors.affiliation: GFZ German Research Centre for Geosciences, Telegrafenberg 14473 Potsdam, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Sens-Schönfelder