Changes in Diffuse Degassing From the Summit Crater of Teide Volcano (Tenerife, Canary Islands) Prior to the 2016 Tenerife Long-Period Seismic Swarm

摘要

Ground surface diffuse degassing and heat flow surveys were conducted at the summit crater of Teide volcano (Tenerife) on a roughly monthly basis from 2013 to 2017 to evaluate their degree of temporal variation and compare with seismovolcanic activity in and around Tenerife Island. We report that significant changes in survey physicochemical and chemical parameters through time were observed. Several geochemical signals record the occurrence of magmatic fluid injections in the hydrothermal system of Tenerife: during June-August of 2016 there were increases in diffuse H2S emission, observed relatively higher values of diffuse H2S/CO2 He/CO2, and CO2/CH4 degassing ratios and changes in the carbon isotopic ratio of diffuse CO2 degassing. Convective mixing within a magma reservoir triggered by an injection of fresh magma is confirmed as the most plausible scenario to explain the source of fluid injection into the hydrothermal system of Teide.