From Magma Source to Volcanic SinkUnder Tagoro Volcano (El Hierro,Canary Islands): Petrologic,Geochemical and PhysiographicEvolution of the 2011–2012 Submarine Eruption

Abstract

Active volcanoes are key laboratories to carryout detailed research -and monitoring- aboutthe history of magmas before, during and aftereruptions. Tagoro, the submarine active volcano at El Hierro Island (Canary archipelago),is a highly favorable case to assess andmonitor its daily ongoing behaviour, as wellas to study the links between the processes ofmagma genesis occurring at depth and theirderived eruptive events at the surface. In thisinterdisciplinary research we combine newresults of classical petrology (petrography,geochemistry, and thermodynamics) on thevolcanic products expelled by Tagoro duringthe 2011–2012 eruption, with a highresolution (5 m grid) bathymetry model carried out during 2017, and recent data frommagnetometry, to refine the current knowledge of this eruption. Our results mainlyreveal (i) slight magma differentiation andmixing processes at c. 12 km depth during acontinuous eruptive pulse; (ii) a similar magmatic evolution and residence times at depthbetween previous and 2011–2012 eruptionson the island; (iii) an insignificant interactionof external fluids with the magma at depth orwithin the ascent conduit; (iv) a present-daymagnetometric anomaly under the Tagoro’sarea; (v) a minimum volume estimate for themagma withdrawn from the plumbing systemat depth.