We investigate global variations in the pattern of aftershock area expansion associated with large subduction zone earthquakes. The expansion of aftershock areas with time is relatively small in the subduction zones of Alaska, the Aleutians, Mexico, and parts of the Kuriles and South America. These subduction zones are interpreted to be characterized by moderate to strong interplate coupling. I...

[1] Much progress has been made over the past several decades in delineating the structure of subducting slabs, but several key aspects of their dynamics remain poorly constrained. Major unsolved problems in subduction geodynamics include those related to mantle wedge viscosity and rheology, slab hydration and dehydration, mechanical coupling between slabs and the ambient mantle, the geometry o...

It is well accepted that subduction of the cold lithosphere is a crucial component of the Earth's plate tectonic style of mantle convection. But whether and how subducting plates penetrate into the lower mantle is the subject of continuing debate, which has substantial implications for the chemical and thermal evolution of the mantle. Here we identify lower-mantle slab penetration events by com...

[1] Based on analysis of data from a trans-Mexico temporary broadband seismic network centered on Mexico City, we report that the subducting Cocos Plate beneath central Mexico is horizontal, and tectonically underplates the base of the crust for a distance of 250 km from the trench. It is decoupled from the crust by a very thin low viscosity zone. The plate plunges into the mantle near Mexico C...

Exhumation has been recognized as an important problem in tectonics and can be achieved by normal faulting, ductile thinning, and erosion. The exhumation of ultrahigh-pressure (UHP) rocks is the most challenging and least understood aspect of the exhumation problem. In this review, we focus on a variety of geologic settings with the goal of characterizing exhumation rates and maximum depths of ...

the study of tectonic evolution of the tethyan and se asian regions indicates that these tworegions have each passed through southwardly progressing sequences of similar tectonic events. both regionshave experienced a southward island-arc subduction and back-arc spreading leading to continentaldetachment from gondwanaland, with an earlier southward island arc subduction of palaeotethys (tethyan...

Lawsonite eclogites represent fossil records of processes occurring during subduction of cold and fast-subducting slabs, and provide the opportunity to investigate the thermal and metamorphic evolution of palaeosubduction zones. Occurrences of lawsonite eclogites are rare because lawsonite is often replaced during exhumation. We report here, for the first time, the occurrence of a lawsonite ecl...

T h e Permo-Carboniferous sedimentary facies development in Thai land reflects the late V a r i s c a n orogeny in S E A s i a . During the Carboniferous and Permian, a N S trending trough separated the " S h a n T h a i C r a t o n " and the " Indosinia C r a t o n " . In this pelagic basin, deposition of ribbon cherts continued from pre-Asselian to Kubergandian. I n L o w e r Permian, carbona...

Subduction, water mass transformation, and transport rates in the Indo-Pacific Ocean are diagnosed in a recent version of the Canadian Centre for Climate Modelling and Analysis coupled model. It is found that the subduction across the base of the winter mixed layer is dominated by the lateral transfer, particularly within the relatively dense water classes corresponding to the densest mode and ...

[1] Dynamic pore pressure changes in the overriding wedge above a shallow-dipping plate interface significantly affect the rupture dynamics of shallow subduction zone earthquakes and their tsunamigenesis. For a wedge on the verge of Coulomb failure everywhere including the basal fault, the dynamic pore pressure increase due to up-dip rupture propagation leads to widespread yielding within the w...