Numerical models of subduction and forearc deformation

Mantle hydration and Cl-rich fluids in the subduction forearc

In the forearc region, aqueous fluids are released from the subducting slab at a rate depending on its thermal state. Escaping fluids tend to rise vertically unless they meet permeability barriers such as the deformed plate interface or the Moho of the overriding plate. Channeling of fluids along the plate interface and Moho may result in fluid overpressure in the oceanic crust, precipitation o...

Homogeneous vs heterogeneous subduction zone models Coseismic and postseismic deformation

A finite-element model (FEM) incorporating geologic properties characteristic of a subduction zone is compared with FEMs approximating homogeneous elastic halfspaces (HEHS)s to investigate the effect of heterogeneity on coseismic and postseismic deformation predictions for the 1995 Colima-Jalisco M•o=8.0 earthquake. The FEMs are used to compute a coefficient matrix relating displacements at obs...

Holocene faulting in the Bellingham forearc basin: Upper-plate deformation at the northern end of the Cascadia subduction zone

[1] The northern Cascadia forearc takes up most of the strain transmitted northward via the Oregon Coast block from the northward-migrating Sierra Nevada block. The north-south contractional strain in the forearc manifests in upper-plate faults active during the Holocene, the northern-most components of which are faults within the Bellingham Basin. The Bellingham Basin is the northern of four b...

Formation of forearc basins and their influence on subduction zone earthquakes

Recent observations of an association between forearc basins and slip during subduction thrust earthquakes suggest a link between processes controlling upper plate structure and seismic coupling on the subduction-zone thrust fault. We present a mechanism for the formation of these basins where sedimentation occurs on landward-dipping segments of the subduction wedge, which itself is actively gr...

Lithium Abundance and Isotope Systematics of Forearc Serpentinites, Conical Seamount, Mariana Forearc: Insights Into the Mechanics of Slab-Mantle Exchange During Subduction