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The surface expressions of subduction zones are arc-trench complexes. On the ocean side of the complex, where the subducting plate first approaches the subduction zone, there is often an outer trench high or outer trench swell. Here the plate shallows slightly before plunging downwards, as a consequence of the rigidity of the plate. [18]
Subduction zones occur where an oceanic plate meets a continental plate and is pushed underneath it. Subduction zones are marked by oceanic trenches. The descending end of the oceanic plate melts and creates pressure in the mantle, causing volcanoes to form. Back-arc basins can form from extension in the overriding plate, in response to the ...
Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. Oceanic trenches are prominent, long, narrow topographic depressions of the ocean floor. They are typically 50 to 100 kilometers (30 to 60 mi) wide and 3 to 4 km (1.9 to 2.5 mi) below the level of the surrounding oceanic ...
The secondary mechanisms view plate motion driven by friction between the convection currents in the asthenosphere and the more rigid overlying lithosphere. This is due to the inflow of mantle material related to the downward pull on plates in subduction zones at ocean trenches.
Subduction zones are caused when two tectonic plates converge on each other and one plate is pushed beneath the other. [34] In a marine setting, this typically occurs when the oceanic crust subducts below the continental crust, resulting in volcanic activity and the development of deep ocean trenches. [35]
Depth of oceanic trenches seems to be controlled by age of the oceanic lithosphere being subducted. [5] Sediment fill in oceanic trenches varies and generally depends on abundance of sediment input from surrounding areas. An oceanic trench, the Mariana Trench, is the deepest point of the ocean at a depth of approximately 11,000 m (36,089 ft).
Melt production and accretion of melt onto continental crust in a subduction zone [1]. A subduction zone is a region of the Earth's crust where one tectonic plate moves under another tectonic plate; oceanic crust gets recycled back into the mantle and continental crust gets produced by the formation of arc magmas.
Moreover, collision of two plates leads to strike slip deformation of the forearc, thus forming a series of features including forearc slivers and strike slip fault systems that are sub-parallel to ocean trenches. [10] In addition, oblique subduction is associated with the closure of ancient ocean, tsunami and block rotations in several regions.