Fig. 1

Subduction zone processes and example of thermal structure. a Cartoon of subduction zone processes that control and are affected by its thermal structure (modified from van Keken (2003)). b Thermal structure predicted for Tohoku (trench-perpendicular cross section below Sendai, Miyagi Prefecture) adopted from van Keken et al. (2012)). T is temperature. Contour lines are shown at every 100\(^\circ\)C. At the decoupling depth \(d_c\) the slab changes from decoupling at shallower depths to full coupling with the overlying mantle wedge. Note that we use the terms coupling and decoupling here and elsewhere in their long-term geodynamical context. This is in contrast with the context of the frictional-elastic seismic cycle at shorter time scales where these terms are used in the opposite sense. Green line: oceanic Moho. Black top line indicated by M is the continental Moho. This cross section shows the predicted thermal structure for an end-member cold subduction zone which is caused by the rapid (8.3 cm/yr) subduction of old (130 Myr) oceanic lithosphere. c Temperature of the top of the oceanic crust (in red) and oceanic Moho (in green) as a function of lithostatic pressure P and depth