An Increasing Trend of the Diffuse CO2 Emission from Teide Volcano (Tenerife, Canary Islands): A Premonitory Geochemical Signature of Volcanic Activity Changes at Tenerife?

Abstract

We report the results of 11 soil CO2 efflux surveys at the summit cone of Teide volcano (SCT), Tenerife. The surveys were undertaken from 1997 to 2009 to determine the scale of total CO2 emissions at the SCT and to evaluate the temporal variations of CO2 efflux and their relationships with the volcanic-seismic activity. Our results reveal significant fluctuations, which do not seem to be masked by external variations, standing out from the rest the ones measured in 2001, and the increasing trend observed from 2007 to 2009, both having similar shapes, intensities, and emission rates. The significant pulse observed in total CO2 emission in 2001 provided the first geochemical observation supporting unrest of the volcanic system, as it was addressed later by anomalous seismic activity recorded in Tenerife Island during April 22-29, 2004 (IGN). The new increasing trend observed from 2007, might be precursor of new anomalous volcanic-seismic activity in the next future, suggesting that subsurface magma movement is the cause for the observed changes in the total output of diffuse CO2 emission at SCT.