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An example of a volcanic arc having both island and continental arc sections is found behind the Aleutian Trench subduction zone in Alaska. Volcanoes that occur above subduction zones, such as Mount St. Helens, Mount Etna, and Mount Fuji, lie approximately one hundred kilometers from the trench in arcuate chains called volcanic arcs.
A volcanic arc is part of an arc-trench complex, which is the part of a subduction zone that is visible at the Earth's surface. A subduction zone is where a tectonic plate composed of relatively thin, dense oceanic lithosphere sinks into the Earth's mantle beneath a less dense overriding plate.
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 displacement of the subducting slab at some oceanic trenches .
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.
Pages in category "Subduction volcanoes" The following 200 pages are in this category, out of approximately 305 total. This list may not reflect recent changes .
The Aleutian island arc formed ~50-55 ma as a result of Kula Plate subduction under the North American Plate before the Pacific plate arrived. [3] There are three stratigraphic units of the Aleutian island arc: volcanic rocks from ~55-33 ma, marine sedimentary rocks from ~23-33 ma, and sedimentary and igneous rocks from ~5 ma-present. [3]
This volcanic series is related to the age of the subduction zone and the depth. The tholeiitic magma series is well represented above young subduction zones formed by magma from relative shallow depth. The calc-alkaline and alkaline series are seen in mature subduction zones, and are related to magma of greater depths.
The subduction zone can be defined by a plane where many earthquakes occur, called the Wadati–Benioff zone. [1] These collisions happen on scales of millions to tens of millions of years and can lead to volcanism, earthquakes, orogenesis , destruction of lithosphere , and deformation .