A volcanic arc is a chain of volcanic islands or mountains formed by plate tectonics as an oceanic tectonic plate subducts under another tectonic plate and produces magma. Plate tectonics and hotspots Divergent plate boundaries At the A mountain is a Landform that extends above the surrounding Terrain in a limited area with a peak Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere Plate tectonics (from Greek τέκτων tektōn "builder" or "mason" describes the large scale motions of Earth 's Lithosphere In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet There are two types of volcanic arcs: oceanic arcs (commonly called island arcs, a type of archipelago) and continental arcs. An archipelago (ɑrkəˈpɛləgoʊ is a chain or cluster of Islands The word archipelago literally means "chief Sea " from Italian In the former, oceanic crust subducts beneath other oceanic crust on an adjacent plate, while in the latter case the oceanic crust subducts beneath continental crust. Oceanic crust is the part of Earth's Lithosphere that surfaces in the Ocean basins The continental crust is the layer of granitic, Sedimentary, and Metamorphic rocks which form the Continents and the areas of shallow seabed In some situations, a single subduction zone may show both aspects along its length, as part of a plate subducts beneath a continent and part beneath adjacent oceanic crust.
Two classic examples of oceanic island arcs are the Mariana Islands in the western Pacific Ocean and the Lesser Antilles in the western Atlantic Ocean. The Mariana Islands (also the Marianas; up to the early 20th century sometimes called Ladrones Islands, from Spanish Islas de los Ladrones meaning The Pacific Ocean is the largest of the Earth 's Oceanic divisions The Lesser Antilles, also known as the Caribbees, are part of the Antilles, which together with the Bahamas and Greater Antilles form the The Cascade Volcanic Arc in western North America and the Andes along the western edge of South America are examples of continental volcanic arcs. The Cascade Volcanoes (also known as the Cascade Volcanic Arc or the Cascade Arc) are a number of Volcanoes in a Volcanic arc in western The Andes form the world's longest exposed Mountain range. They lie as a continuous chain of highland along the western coast of South America. South America is a Continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a The best examples of volcanic arcs with both sets of characteristics are in the North Pacific, with the Aleutian Arc consisting of the Aleutian Islands and their extension the Aleutian Range on the Alaska Peninsula, and the Kuril-Kamchatka Arc comprising the Kuril Islands and southern Kamchatka Peninsula. The Aleutian Islands (possibly from Chukchi aliat, " Island " are a chain of more than 300 small volcanic islands forming a Volcanic The Aleutian Range is a major Mountain range of southwest Alaska, extending from Chakachamna Lake (80 miles/130 km southwest of Anchorage to Unimak The Alaska Peninsula is a Peninsula extending about 800 km (500 miles to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The Kuril Islands (ˈkʊrɪl or /ˈkjuˈriˈl/ Кури́льские острова́ əstrʌˈva ru-Latn ''Kuril'skie ostrova'' or Kurile Islands in Russia
In the subduction zone, loss of volatiles from the subducted slab induces partial melting of the overriding mantle and generates low-density, calc-alkaline magma that buoyantly rises to intrude and be extruded through the lithosphere of the overriding plate. In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other In Planetary science, volatiles, are that group of elements and compounds with low boiling points (see volatile) that are associated with a planet's or moon's The mantle is a part of an Astronomical object. The interior of the Earth, similar to the other Terrestrial planets, is Chemically divided Calc-alkaline and calc-alkalic are equivalent terms applied to groups of Igneous rocks that commonly occur together and that have compositions related by the characteristic Magma (Plurals magmas and magmata) is molten rock that sometimes forms beneath the surface of the Earth (or any other Terrestrial planet In Geology, an intrusion is a body of Igneous rock that has Crystallized from molten Magma below the surface of the Earth. The lithosphere (IPA, from the Greek λίθος for "rocky" + σφαίρα for "sphere" is the solid outermost shell of a rocky Planet.
On the subducting side of the island arc is a deep and narrow oceanic trench, which is the trace at the Earth’s surface of the boundary between the downgoing and overriding plates. The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor This trench is created by the gravitational pull of the relatively dense subducting plate pulling the leading edge of the plate downward. Multiple earthquakes occur along this subduction boundary with the seismic hypocenters located at increasing depth under the island arc: these quakes define the Wadati-Benioff zones. An earthquake is the result of a sudden release of energy in the Earth 's crust that creates Seismic waves Earthquakes are recorded with a Seismometer Seismology (from Greek grc σεισμός seismos, "earthquake" and grc -λογία -logia) is the scientific study of Earthquakes The hypocenter or hypocentre (literally 'below the center' from the Greek υπόκεντρον) refers to the site of an earthquake or to that of a nuclear A Wadati-Benioff zone (also Benioff-Wadati zone or Benioff zone) is a deep active seismic area in a Subduction zone
Ocean basins that are being reduced by subduction are called 'remnant oceans' as they will slowly be shrunken out of existence and crushed in the subsequent orogenic collision. Orogeny (Greek for "mountain generating" is the process of natural Mountain building and may be studied as a tectonic structural event as a geographical event and This process has happened over and over in the geologic history of the Earth.