The Long-term Evolution of Subduction Zones: A Modelling Study

670 km depth 670 km discontinuity background mantle flow beneath cessation of subduction chapter cm/yr cm/yr Vm convergence velocity depth km descending slab descent velocity dip angle dipping subduction zones Earth Planet Earth's mantle effective trench migration factor of 50 geoid Geophys Hager harzburgite horizontal increase in viscosity increases at 670 indicate Izu Bonin layer lithosfeer lower mantle lower mantle viscosity mantle convection model domain model temperature Myr after subduction observed old lithosphere olivine P-wave P-wave velocity anomaly phase transition plaat plate velocities Rayleigh number reference viscosity seismic velocity anomaly shown in Figure shows slab geometry slab penetration slab structure Spakman spinel strongly time-dependent subducted lithosphere subducting slab subduction process subduction zone geometry surface viscosity tectonic temperature anomaly temperature field temperature structure thermal tomographic images tracer trajectories transition zone trench migration rate underthrusting plate upper mantle viscosity viscosity increases viscosity profile west dipping subduction wordt Wortel young lithosphere zero