From Magma Source to Volcanic Sink Under Tagoro Volcano (El Hierro, Canary Islands): Petrologic, Geochemical and Physiographic Evolution of the 2011-2012 Submarine Eruption

Abstract

Active volcanoes are key laboratories to carry out detailed research -and monitoring- about the history of magmas before, during and after eruptions. Tagoro, the submarine active volcano at El Hierro Island (Canary archipelago), is a highly favorable case to assess and monitor its daily ongoing behaviour, as well as to study the links between the processes of magma genesis occurring at depth and their derived eruptive events at the surface. In this interdisciplinary research we combine new results of classical petrology (petrography, geochemistry, and thermodynamics) on the volcanic products expelled by Tagoro during the 2011–2012 eruption, with a high-resolution (5 m grid) bathymetry model carried out during 2017, and recent data from magnetometry, to refine the current knowledge of this eruption. Our results mainly reveal (i) slight magma differentiation and mixing processes at c. 12 km depth during a continuous eruptive pulse; (ii) a similar magmatic evolution and residence times at depth between previous and 2011–2012 eruptions on the island; (iii) an insignificant interaction of external fluids with the magma at depth or within the ascent conduit; (iv) a present-day magnetometric anomaly under the Tagoro’s area; (v) a minimum volume estimate for the magma withdrawn from the plumbing system at depth.