Influence of lateral slab edge distance on plate velocity, trench velocity, and subduction partitioning

Cenozoic tectonics of western North America controlled by evolving width of Farallon slab.

Subduction of oceanic lithosphere occurs through two modes: subducting plate motion and trench migration. Using a global subduction zone data set and three-dimensional numerical subduction models, we show that slab width (W) controls these modes and the partitioning of subduction between them. Subducting plate velocity scales with W(2/3), whereas trench velocity scales with 1/W. These findings ...

The effect of a power-law mantle viscosity on trench retreat rate

S U M M A R Y The subduction of lithospheric plates is partitioned between subducting platemotion and lateral slab migration (i.e. trench retreat and advance). We use 3-D, dynamic models of subduction to address the role of a power-law mantle viscosity on subduction dynamics and, in particular, rates of trench retreat. For all numerical models tested, we find that a power-law rheology results i...

Trench migration and overriding plate stress in dynamic subduction models

S U M M A R Y On Earth, oceanic plates subduct beneath a variety of overriding plate (OP) styles, from relatively thin and negatively buoyant oceanic OPs to thick and neutrally/positively buoyant continental OPs. The inclusion of an OP in numerical models of self-consistent subduction has been shown to reduce the rate that subducting slabs roll back relative to the equivalent single plate model...

Tomographic image of low P velocity anomalies above slab in northern Cascadia subduction zone

At the Cascadia margin the Juan de Fuca plate is subducting beneath the North America plate, causing active seismicity within both plates. Earthquakes occur down to a maximum depth of 80 km within the descending oceanic plate and to about 30 km in the overriding continental plate. We use a method of seismic tomography to invert 28,230 P wave arrival times from 2666 local earthquakes that occurr...

Velocity and Distance of NeighbourhoodSequencesAndr