Skip to content

Mechanical implications of a hydrothermal core within Teide volcano, Tenerife

Claire E. Harnett1 , Michael J. Heap2, 3, Davitia James4, Benjamin De Jarnatt4, Pablo J. González5, Thomas Boulesteix5, Thomas R. Walter4, Valentin R. Troll6

  • Affiliations:  1 UCD School of Earth Sciences, University College Dublin, Dublin, Ireland; 2 Université de Strasbourg, CNRS, Institut Terre et Environnement de Strasbourg, UMR 7063, 5 Rue Descartes, Strasbourg F-67084, France; 3 Institut Universitaire de France (IUF), Paris, France; 4 GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany; 5 Instituto de Productos Naturales y Agrobiologia, Consejo Superior de Investigaciones Cientificas; 6 Department of Earth Sciences, Natural Resources and Sustainable Development, University of Uppsala, Uppsala 

  • Presentation type: Poster

  • Presentation time: Thursday 16:30 - 18:30, Room Poster Hall

  • Poster Board Number: 27

  • Programme No: 3.8.11

  • Theme 3 > Session 8

Abstract

Tenerife (Canary Islands) has undergone several north-directed lateral collapses. Previous studies have suggested that the active stratovolcano Teide in central Tenerife continues to exhibit potential flank instability to the north related to ongoing volcano spreading, which is thought to accelerate during magmatic and hydrothermal episodes. While outward displacement commensurate with spreading is not observed, morphological and structural features have still been linked to possible spreading. The volcano shows a concave slope profile on the northern flank, as well as normal faulting at the summit. These features may imply (1) a gently dipping low-strength breccia layer at the base of the volcano, facilitating large-scale spreading; and (2) the presence of a hydrothermally altered core and crater area later overgrown by the edifice. Here, we test these ideas using a combination of high-resolution drone imagery, rock mechanics testing, and computational modelling. We test rock samples from the (1) pre-medieval Teide cone (Old Teide); (2) Old Teide's crater rim; (3) Teide's new summit cone; and (4) lava that descended downslope from Teide's most recent summit eruption (Lavas Negras) and quantify the physical and mechanical properties for the different stratigraphic units. We then perform simple finite element method modelling that incorporates these rock properties for a simplified stratigraphy and incorporates a hydrothermally weakened core. We investigate whether the observed slope concavity can be reproduced considering only mechanical weakening from an altered core.