Fig. 2
From: Structural control and system-level behavior of the seismic cycle at the Nankai Trough
Conceptual model and physical parameters for the down-dip segmentation of the megathrust and the ductile substrate. a Synoptic look at the relationship between brittle and ductile processes with a subduction zone geometry. The megathrust is segmented into the accretionary prism (segment A), seismogenic zone (segment B), metamorphic belt (segment C), mantle lid (segment D), and mantle wedge (segment E). The friction properties of these regions are controlled by the thermo-mechanical properties at the plate interface. The brittle–ductile transition occurs seaward of the volcanic arc. Corner flow in the mantle wedge starts landward of this boundary, in the mantle wedge asthenosphere. b Friction parameters \(a-b\) and L of segments A to E, and c corresponding \(R_u\) and \(R_b\) numbers. d Static friction coefficient and loading rate along the megathrust. e Rheological parameters of the oceanic asthenosphere at steady state. f Rheological parameters of the mantle wedge at steady state. g Thermal gradient in the upper mantle