Great earthquakes, the few largest earthquakes that account for most of the Earth’s seismic energy release, have occurred at only a few subduction zones around the world. Strong locking, or ‘seismic coupling’, of the interface between plates at certain subduction zones is often invoked to explain these great earthquakes. Although past studies have correlated strong seismic coupling with a compr...

A large amount of water is brought into the Earth’s mantle at subduction zones. Upon subduction, water is released from the subducting slab in a series of metamorphic reactions. The resulting flux into the mantle wedge modifies its chemical and physical properties by mineral hydration with associated weakening, flux melting and changes in the dynamics and thermal structure of subduction zones. ...

Despite good evidence of present-day convergence of the Juan de Fuca and North American plates, there has been remarkably little historical seismic activity along the shallow part of the Juan de Fuca subduction zone. Although we cannot completely rule out the possibility that the plate motion is being accommodated by aseismic creep, we find that the Juan de Fuca subduction zone shares many feat...

Despite good evidence of present-day convergence of the Juan de Fuca and North American plates, there has been remarkably little historical seismic activity along the shallow part of the Juan de Fuca subduction zone. Although we cannot completely rule out the possibility that the plate motion is being accommodated by aseismic creep, we find that the Juan de Fuca subduction zone shares many feat...

We present major and trace element concentrations in conjunction with Sr–Nd isotope ratios to investigate the geochemical characteristics of mélange formation along the subduction zone slab–mantle interface. Mélange matrix of the Catalina Schist formed within an active subduction zone of the southern California borderland in Cretaceous time. Mélange formed through the synergistic effects of def...

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...

Earth is the only known planet with subduction zones and plate tectonics, and this fact demonstrates that special conditions are required for this mode of planetary heat loss. Sinking of cold, dense lithosphere in subduction zones is the principal plate-driving force, so plate tectonics could not have begun until Earth cooled sufficiently to allow lithosphere to collapse into the underlying ast...

Despite its importance for ourunderstandingof physical processes associatedwith subduction, the geometry of mantle flow in subduction zones remains poorly understood, particularly in the mantle wedge above subducting slabs. Constraints onmantle flowanddeformation canbeobtainedbymeasurements of shearwave splitting, a valuable tool used to characterize the geometry and strength of seismic anisotr...

By enhancing mass transfer and energy release, the cycle of volatiles and melt is a major component of subduction. Investigating this fluid cycle is therefore critical to understand the past and current activity of subduction zones. Fluids can significantly affect rock electrical conductivity and elastic parameters that are measured using electromagnetic and seismic methods, respectively. This ...