Metamorphism associated with orogenesis provides a mineral record that may be inverted to yield ambient apparent thermal gradients. On modern Earth, tectonic settings with lower thermal gradients are characteristic of subduction zones whereas those with higher thermal gradients are characteristic of backarcs and orogenic hinterlands. The duality of thermal environments reflects the asymmetry of...

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...

Citation: Tesfamariam S and Goda K (2017) Energy-Based Seismic Risk Evaluation of Tall Reinforced Concrete Building in Vancouver, BC, Canada, under Mw9 Megathrust Subduction Earthquakes and Aftershocks. Front. Built Environ. 3:29. doi: 10.3389/fbuil.2017.00029 Energy-Based Seismic Risk Evaluation of Tall Reinforced Concrete Building in Vancouver, BC, Canada, under Mw9 Megathrust Subduction Eart...

Subduction systems are vitally important to plate tectonics and mantle convection, but questions remain about many aspects of subduction dynamics, particularly the nature of sub-slab mantle flow. Observations of seismic anisotropy can shed light on the pattern of mantle flow in subduction systems, but major uncertainties remain regarding the interpretation of sub-slab anisotropy. Here, we prese...

[1] An approach to invert GPS time series to estimate crustal block rotations, fault locking and strain rates while simultaneously solving for transient slow slip events is described and applied to the northern Cascadia subduction zone. The method can use continuous or survey mode GPS time series or both. I invert 5.6 years of 3-component continuous GPS time series at 53 sites from Cascadia to ...

The October, 1995 Mw 8.0 Jalisco subduction earthquake has provided a thorough geodetic observation of the coseismic subduction process. An 11 station regional GPS network located directly onshore of the rupture demonstrates consistent vertical subsidence verified by tide gauge data and southwest-directed extension, with measured displacements reaching I meter. Unusually shallow and non-uniform...

The supposed low viscosity of serpentine may strongly influence subduction-zone dynamics at all time scales, but until now its role could not be quantified because measurements relevant to intermediate-depth settings were lacking. Deformation experiments on the serpentine antigorite at high pressures and temperatures (1 to 4 gigapascals, 200 degrees to 500 degrees C) showed that the viscosity o...

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...

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...

The transfer (accretion) of materials from a subducting oceanic plate to a subduction-accretionary complex has produced rock assemblages recording the history of the subducted oceanic plate from formation to arrival at the trench. These rock assemblages, comprising oceanic igneous rocks progressively overlain by pelagic sedimentary rocks (chert and/or limestone) and trench-fill clastic sediment...