We have used sandbox experiments to explore the mechanics of the frontal prism structures
documented by seismic reflection data and new borehole from IODP Expedition 343
(JFAST). This study investigated the effects of down-dip (normal to trench axis) variations in
frictional resistance along a decollement on the structural development of the frontal wedges
near subduction zones. Interpretation of seismic reflection images indicates that the wedge
has been effected by trench-parallel horst-and-graben structures in the subducting plate. We …

Subduction of bathymetric features in the oceanic plate, eg, seamounts, aseismic ridges,
volcanic plateaus has a strong influence on the development of morphological features and
deformation structures in the overriding plate. For example, the subduction of seamounts
correlates to a steeper surface slope in the inner wedge than that in the outer wedge.
Conversely, the subduction of aseismic ridges causes the development of a steep outer
wedge slope and with almost flat inner wedge. Despite the dominance of horst-and-graben …