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Download as PDF; Printable version; In other projects ... Pages in category "Subduction zones" The following 52 pages are in this category, out of 52 total.
The figure is a schematic diagram depicting a subduction zone. The subduction slab on the right enters the mantle with a varying temperature gradient while importing water in a downward motion. A model of the subducting Farallon slab under North America. In geology, the slab is a significant constituent of subduction zones. [1]
Obduction zones occurs when the continental plate is pushed under the oceanic plate, but this is unusual as the relative densities of the tectonic plates favours subduction of the oceanic plate. This causes the oceanic plate to buckle and usually results in a new mid-ocean ridge forming and turning the obduction into subduction. [citation needed]
The subduction of bathymetric highs such as aseismic ridges, oceanic plateaus, and seamounts has been posited as the primary driver of flat slab subduction. [3] The Andean flat slab subduction zones, the Peruvian slab and the Pampean (Chilean) flat slab, are spatially correlated with the subduction of bathymetric highs, the Nazca Ridge and the Juan Fernandéz Ridge, respectively.
Subduction zone physics: Sinking of the oceanic lithosphere (sediments, crust, mantle), by the contrast of density between the cold and old lithosphere and the hot asthenospheric mantle wedge, is the strongest force (but not the only one) needed to drive plate motion and is the dominant mode of mantle convection. [citation needed]
The Kermadec–Tonga subduction zone is a convergent plate boundary that stretches from the North Island of New Zealand northward. The formation of the Kermadec and Tonga plates started about 4–5 million years ago. Today, the eastern boundary of the Tonga plate is one of the fastest subduction zones, with a rate up to 24 cm/year (9.4 in/year ...
The Tonga–Kermadec Ridge is an oceanic ridge in the south-west Pacific Ocean underlying the Tonga–Kermadec island arc.It is a result of the most linear, fastest converging, and seismically active subduction boundary on Earth, the Kermadec–Tonga subduction zone, and consequently has the highest density of submarine volcanoes.
Subduction zones host a unique variety of rock types formed by the high-pressure, low-temperature conditions a subducting slab encounters during its descent. [4] The metamorphic conditions the slab passes through in this process generates and alters water bearing (hydrous) mineral phases, releasing water into the mantle.