Fig. 2. Left: Two models of seismic attenuation at latitude 24 S of the Andean Subduction zone after Whitman et al. (1992). Model on top shows a gradual brittle-ductile transition from lithosphere to asthenosphere whereas the bottom model shows and abrupt transition.
Right: Resistivity model of the backarc zone at same latitude, showing an agreement between the thermal boundary layer (TBL) that defines the top of the electrical asthenosphere with the abrupt transition from lithosphere to asthenosphere of the seismic attenuation model of the bottom left (after Lezaeta et al., 2000).