[1] We give an explanation for the polarity, localization, shape, size, and initiation of subduction zones on Earth. By considering a soft, thin, curved lithospheric cap with either elastic or viscous rheology supported by a thick, nearly incompressible mantle, we find two different characteristic subduction geometries arise depending on boundary conditions: (1) plate boundaries where subductio...

Large subduction earthquakes on the Cascadia subduction zone pose a potential seismic hazard. Very young oceanic lithosphere (10 million years old) is being subducted beneath North America at a rate of approximately 4 centimeters per year. The Cascadia subduction zone shares many characteristics with subduction zones in southern Chile, southwestern Japan, and Colombia, where comparably young oc...

Flat slab subduction has been attributed to various causes including mantle wedge dynamics, overriding by the upper plate, age of the subducting plate, and subduction of anomalously thick oceanic crust. One often favored explanation for flat slabs is the subduction of buoyant features on the oceanic plate in the form of an aseismic-ridge or oceanic plateau. We show through plate tectonic recons...

Owing to the importance of serpentinites for planetary geochemical and geodynamic processes, there has been much work discerning origins their parent rocks, including distinguishing between derived from a subducting plate versus overlying mantle in exhumed subduction complexes. The island New Caledonia (SW Pacific Ocean) provides rare window into Cenozoic processes. is unique exposing both an e...

Voluminous flux of a hydrous component from subducting oceanic lithosphere into the forearc mantle and its contribution to arc magmas have long been recognised but transfer solid-phase materials has received less consideration. Although xenocrystic zircons are known some ophiolitic chromitites their origins remain enigmatic. How when such transferred overlying wedge length residency therein unc...

Ophiolites, fragments of oceanic lithosphere exposed on land, are typically found as isolated klippen in intensely deformed fold-thrust belts spanning hundreds to thousands kilometers along-strike. Ophiolites whose geochemistry indicates that they formed above subduction zones, may have been relics larger, once-coherent, tracts the leading edge an upper plate below which occurred; such were sub...

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...

[1] The mean residence times, subduction rates, and formation rates of Subtropical Mode Water (STMW) and Subpolar Mode Water (SPMW) in the North Atlantic and Subantarctic Mode Water (SAMW) in the Southern Ocean are estimated by combining a model and observations of chlorofluorocarbon-11 (CFC-11) via Bayesian Model Averaging (BMA), a statistical technique that weights model estimates according t...