Preliminary geomorphological analysis of the Tagoro Volcano underwater eruption (submarine slope of El Hierro Island)

Abstract

Between October 2011 and March 2012 a submarine volcanic eruption took place at the offshore of El Hierro Island. The extensive study of the eruption and subsequent degassing process has allowed monitoring the newly generated volcanic edifice. Multibeam bathymetric has enabled building a digital high-resolution bathymetric model (grid 1x1 m). The preliminary analysis of the geomorphology of this volcanic eruption displays four main features: i) the edifice consists of a principal and a series of secondary cones distributed in NW-SE trend; ii) two escarpments NE-SW directed that partially match with inherited flanks of the previously existing valley; iii) three crests, one of them interpreted as the prolongation of a NE-SW scarp and the other as the head of gravitational instabilities of NE-SW and N-S direction at the main hill; and iv) mixed lava and dense pyroclastic flows extended from the volcanic edifice to the southwest and characterized by a high slope front, that probably represents the maximum distance reached by the main lava products.