  In this work we have done a 3D joint interpretation of magnetotelluric and
seismic tomography models. Previously we have described different techniques to
infer the inner structure of the Earth. We have focused on volcanic regions,
specifically on Tenerife Island volcano (Canary Islands, Spain). In this area,
magnetotelluric and seismic tomography studies have been done separately. The
novelty of the present work is the combination of both techniques in Tenerife
Island. For this aim we have applied Fuzzy Clusters Method at different depths
obtaining several clusters or classes. From the results, a geothermal system
has been inferred below Teide volcano, in the center of Tenerife Island. An
edifice hydrothermally altered and full of fluids is situated below Teide,
ending at 600 m below sea level. From this depth the resistivity and VP values
increase downwards. We also observe a clay cap structure, a typical feature in
geothermal systems related with low resistivity and low VP values.
