| Titre | Magma storage and migration associated with the 2011-2012 El Hierro eruption: Implications for crustal magmatic systems at oceanic island volcanoes |
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| Auteur | González, P J; Samsonov, S V ; Pepe, S; Tiampo, K F; Tizzani, P; Casu, F; Fernández, J; Camacho, A G; Sansosti, E |
| Source | Journal of Geophysical Research vol. 118, issue 8, 2013 p. 4361-4377, https://doi.org/10.1002/jgrb.50289  Accès ouvert |
| Image |  |
| Année | 2013 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20130481 |
| Éditeur | Wiley-Blackwell |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1002/jgrb.50289 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Région | El Hierro Island; Canary Islands |
| Lat/Long OENS | -18.1667 -17.8333 28.0000 27.5000 |
| Sujets | volcans; magmas; sismicité; télédétection; établissement de modèles; cristallisation; cristallisation fractionnée; géodésie par satellite; géophysique |
| Illustrations | analyses |
| Diffusé | 2013 08 06 |
| Résumé | (disponible en anglais seulement)
Starting in July 2011, anomalous seismicity was observed at El Hierro Island, a young oceanic island volcano. On 12 October 2011, the process led to the
beginning of a submarine NW-SE fissural eruption at ~15 km from the initial earthquake loci, indicative of significant lateral magma migration. Here we conduct a multifrequency, multisensor interferometric analysis of spaceborne radar images acquired
using three different satellite systems (RADARSAT-2, ENVISAT, and COSMO-SkyMed (Constellation of Small Satellites for Mediterranean Basin Observation)). The data fully captures both the pre-eruptive and coeruptive phases. Elastic modeling of the
ground deformation is employed to constrain the dynamics associated with the magmatic activity. This study represents the first geodetically constrained active magmatic plumbing system model for any of the Canary Islands volcanoes, and one of the few
examples of submarine volcanic activity to date. Geodetic results reveal two spatially distinct shallow (crustal) magma reservoirs, a deeper central source (9.5 ± 4.0 km), and a shallower magma reservoir at the flank of the southern rift (4.5 ± 2.0
km). The deeper source was recharged, explaining the relatively long basaltic eruption, contributing to the observed island-wide uplift processes, and validating proposed active magma underplating. The shallowest source may be an incipient reservoir
that facilitates fractional crystallization as observed at other Canary Islands. Data from this eruption supports a relationship between the depth of the shallow crustal magmatic systems and the long-term magma supply rate and oceanic lithospheric
age. Such a relationship implies that a factor controlling the existence/depth of shallow (crustal) magmatic systems in oceanic island volcanoes is the lithosphere thermomechanical behavior. |
| GEOSCAN ID | 293732 |
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