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Volcanic arc
 
 
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A volcanic arc is a chain of volcanic island
Volcano

A volcano is an opening, or rupture, in a planet's surface or Crust , which allows hot, molten rock, ash, and gases to escape from below the surface....
s or mountain
Mountain

A mountain is a landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill....
s formed by plate tectonics
Plate tectonics

Plate tectonics describes the large scale motions of Earth's lithosphere. The theory encompasses the older concepts of continental drift, developed during the first decades of the 20th century by Alfred Wegener, and seafloor spreading, understood during the 1960s....
 as an oceanic tectonic plate
Tectonic Plate

#REDIRECT Plate tectonics...
 subducts
Subduction

In geology, subduction is the process that takes place at convergent boundary by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge....
 under another tectonic plate and produces magma
Magma

Magma is molten Rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles....
. There are two types of volcanic arcs: oceanic arcs (commonly called island arcs, a type of archipelago
Archipelago

An archipelago is a chain or cluster of islands that are formed tectonically. The word archipelago literally means "chief sea", from Italian language arcipelago , derived ultimately from Greek language arkhon and pelagos ....
) and continental arcs.






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Casta Marianas
A volcanic arc is a chain of volcanic island
Volcano

A volcano is an opening, or rupture, in a planet's surface or Crust , which allows hot, molten rock, ash, and gases to escape from below the surface....
s or mountain
Mountain

A mountain is a landform that stretches above the surrounding land in a limited area usually in the form of a peak. A mountain is generally steeper than a hill....
s formed by plate tectonics
Plate tectonics

Plate tectonics describes the large scale motions of Earth's lithosphere. The theory encompasses the older concepts of continental drift, developed during the first decades of the 20th century by Alfred Wegener, and seafloor spreading, understood during the 1960s....
 as an oceanic tectonic plate
Tectonic Plate

#REDIRECT Plate tectonics...
 subducts
Subduction

In geology, subduction is the process that takes place at convergent boundary by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge....
 under another tectonic plate and produces magma
Magma

Magma is molten Rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles....
. There are two types of volcanic arcs: oceanic arcs (commonly called island arcs, a type of archipelago
Archipelago

An archipelago is a chain or cluster of islands that are formed tectonically. The word archipelago literally means "chief sea", from Italian language arcipelago , derived ultimately from Greek language arkhon and pelagos ....
) and continental arcs. In the former, oceanic crust
Oceanic crust

Oceanic crust is the part of Earth's lithosphere that surfaces in the ocean basins. Oceanic crust is primarily composed of mafic rocks, or Sima ....
 subducts beneath other oceanic crust on an adjacent plate, while in the latter case the oceanic crust subducts beneath continental crust
Continental crust

The continental crust is the layer of igneous, sedimentary, and metamorphic rocks which form the continents and the areas of shallow seabed close to their shores, known as Continental shelf....
. 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
Mariana Islands

The Mariana Islands are an archipelago made up by the summits of 15 volcanic mountains in the north-western Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east....
 in the western Pacific Ocean
Pacific Ocean

The Pacific Ocean is the largest of the Earth's oceanic divisions. Its name is derived from the Latin name Mare Pacificum, "peaceful sea", bestowed upon it by the Portugal explorer Ferdinand Magellan....
 and the Lesser Antilles
Lesser Antilles

The Lesser Antilles, also known as the Caribbees, are part of the Antilles, which together with the Bahamas, the Turks and Caicos Islands, and Greater Antilles form the West Indies....
 in the western Atlantic Ocean
Atlantic Ocean

The Atlantic Ocean is the second-largest of the world's oceanic divisions; with a total area of about 106.4 million square kilometres . It covers approximately one-fifth of the Earth's surface....
. The Cascade Volcanic Arc
Cascade Volcanoes

The Cascade Volcanoes are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 mi ....
 in western North America
North America

North America is the northern continent of the Americas, situated in the Earth's northern hemisphere and almost totally in the western hemisphere....
 and the Andes
Andes

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. The range is over 7,000 km long, 200-700 km wide , and of an average height of about 4,000 m ....
 along the western edge of South America
South America

South America is the southern continent of the Americas, situated entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere....
 are examples of continental volcanic arcs. 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
Aleutian Islands

The Aleutian Islands are a chain of more than 300 small volcanic islands forming a volcanic arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi and extending about 1,200 mi westward from the Alaska Peninsula toward the Kamchatka Peninsula....
 and their extension the Aleutian Range
Aleutian Range

The Aleutian Range is a major mountain range of southwest Alaska, extending from Chakachamna Lake to Unimak Island, at the tip of the Alaska Peninsula....
 on the Alaska Peninsula
Alaska Peninsula

The Alaska Peninsula is a peninsula extending about 800 km to the southwest from the mainland of Alaska and ending in the Aleutian Islands....
, and the Kuril-Kamchatka Arc comprising the Kuril Islands
Kuril Islands

The Kuril Islands or Kurile Islands in Russia's Sakhalin Oblast region, is a volcanic archipelago that stretches approximately 1,300 km northeast from Hokkaido, Japan, to Kamchatka Peninsula, Russia, separating the Sea of Okhotsk from the North Pacific Ocean....
 and southern Kamchatka Peninsula
Kamchatka Peninsula

The Kamchatka Peninsula is a 1,250-kilometer long peninsula in the Russian Far East, with an area of 472,300 km?. It lies between the Pacific Ocean to the east and the Sea of Okhotsk to the west....
.

Petrology

In the subduction zone
Subduction

In geology, subduction is the process that takes place at convergent boundary by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge....
, loss of water
Water

Water is a common chemical substance that is essential for the survival of all known forms of life. In typical usage, water refers only to its liquid form or States of matter, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam....
 from the subducted slab induces partial melting of the overriding mantle
Mantle (geology)

The mantle is a part of an astronomical object. The interior of the Earth, similar to the other terrestrial planets, is chemically divided into layers....
 and generates low-density, calc-alkaline
Calc-alkaline

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 chemical trends specified below....
 magma
Magma

Magma is molten Rock that is found beneath the surface of the Earth, and may also exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and gas bubbles....
 that buoyantly rises to intrude
Intrusion

In geology, an intrusion is a body of igneous rock that has crystallized from molten magma below the surface of the Earth. Bodies of magma that solidify underground before they reach the surface of the earth are called plutons, named for Pluto , the Roman mythology of the underworld....
 and be extruded through the lithosphere
Lithosphere

File:Plates tect2 en.svgFile:Earth-crust-cutaway-english.svgThe lithosphere is the rigid outermost shell of a rocky planet....
 of the overriding plate. This loss of water is due to the destabilization of the mineral chlorite
Chlorite group

The chlorites are a group of Silicate minerals minerals. Chlorites can be described by the following four Solid solution based on their chemistry via substitution of the following four elements in the silicate lattice; Mg, Fe, Ni, and Mn....
 at approximately 40-60 km depth. This is the reason for island arc volcanism at consistent distances from the subducting slab: because the temperature-pressure conditions for flux-melting volcanism due to chlorite destabilization will always occur at the same depth, the distance from the trench to the arc volcanoes is determined only by the dip angle of the subducting slab.

On the subducting side of the island arc is a deep and narrow oceanic trench
Oceanic trench

The oceanic trenches are hemispheric-scale long but narrow topographic depressions of the sea floor. They are also the deepest parts of the ocean floor....
, which is the trace at the Earth’s surface of the boundary between the downgoing and overriding plates. This trench is created by the gravitational pull of the relatively dense subducting plate pulling the leading edge of the plate downward. Multiple earthquake
Earthquake

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, also known as a seismograph....
s occur along this subduction boundary with the seismic hypocenter
Hypocenter

The hypocenter or hypocentre , refers to the site of an earthquake or to that of a nuclear explosion. In the former, it is a synonym of the focus; in the latter, of ground zero....
s located at increasing depth under the island arc: these quakes define the Wadati-Benioff zones.

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
Orogeny

Orogeny refers to natural mountain building, and may be studied as a tectonic structural event, as a geographical event, and a chronological event: orogenic events cause distinctive structural phenomena and related tectonic activity, affect certain regions of rocks and crust, and happen within a specific period of time....
 collision. This process has happened over and over in the geologic history of the Earth.

Map of Alaska Volcanoes Okmok

Examples


Continental arcs
  • Cascade Volcanic Arc
    Cascade Volcanoes

    The Cascade Volcanoes are a number of volcanoes in a volcanic arc in western North America, extending from southwestern British Columbia through Washington and Oregon to Northern California, a distance of well over 700 mi ....
  • Alaska Peninsula
    Alaska Peninsula

    The Alaska Peninsula is a peninsula extending about 800 km to the southwest from the mainland of Alaska and ending in the Aleutian Islands....
     and Aleutian Range
    Aleutian Range

    The Aleutian Range is a major mountain range of southwest Alaska, extending from Chakachamna Lake to Unimak Island, at the tip of the Alaska Peninsula....
  • Kamchatka
  • Andes
    Andes

    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. The range is over 7,000 km long, 200-700 km wide , and of an average height of about 4,000 m ....
    • North Volcanic Zone
      North Volcanic Zone

      The North Volcanic Zone is a volcanic arc in northwestern South America. It is one of the four volcanic zones of the Andes. The North Volcanic Zone extends from Colombia to Ecuador....
    • Central Volcanic Zone
      Central Volcanic Zone

      The Central Volcanic Zone is a volcanic arc in western South America. It is one of the four volcanic zones of the Andes. The Central Volcanic Zone extends from Peru to Chile and forms the western boundary of the Altiplano plateau....
    • South Volcanic Zone
      South Volcanic Zone

      The South Volcanic Zone is a volcanic arc in southwestern South America. It is one of the four volcanic zones of the Andes. The SVZ extends roughly from Central Chile's Andes at the latitude of Santiago, Chile to Mount Hudson in Ays?n Region, a distance of well over 870 mi ....
    • Austral Volcanic Zone
      Austral Volcanic Zone

      The Austral Volcanic Zone is a volcanic arc in the Andes of southwestern South America. It is one of the four volcanic zones of the Andes. The AVZ extends from the Chile Triple Junction to Tierra del Fuego archipelago, a distance of well over 600 mi ....
  • Central America Volcanic Arc


Island arcs
  • Aleutian Islands
    Aleutian Islands

    The Aleutian Islands are a chain of more than 300 small volcanic islands forming a volcanic arc in the Northern Pacific Ocean, occupying an area of 6,821 sq mi and extending about 1,200 mi westward from the Alaska Peninsula toward the Kamchatka Peninsula....
  • Kuril Islands
    Kuril Islands

    The Kuril Islands or Kurile Islands in Russia's Sakhalin Oblast region, is a volcanic archipelago that stretches approximately 1,300 km northeast from Hokkaido, Japan, to Kamchatka Peninsula, Russia, separating the Sea of Okhotsk from the North Pacific Ocean....
  • Japan
    Japan

    Japan is an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south....
     and Ryukyu Islands
    Ryukyu Islands

    The Ryukyu Islands are part of the . From around 1800 on, they have spelled Luchu, Loo-choo, or Lewchew, from the Chinese Liuqiu. They consist of a chain of Islands of Japan in the western Pacific Ocean at the eastern limit of the East China Sea and stretch southwest from the island of Kyushu to the island of Taiwan....
  • Izu-Bonin-Mariana Arc
    Izu-Bonin-Mariana Arc

    [Image:IBM-Locality.jpg|thumb|right|250px|The Izu-Bonin-Mariana arc system is an outstanding example of a plate tectonic convergent boundary. IBM extends over 2800 km south from near Tokyo, Japan, to beyond Guam, and includes the Izu Islands....
    :
    • Izu Islands
      Izu Islands

      The are a group of volcanic islands stretching south and east from the Izu Peninsula of Honshu, Japan. Administratively, they form two towns and six villages; all part of Tokyo....
    • Bonin Islands
    • Mariana Islands
      Mariana Islands

      The Mariana Islands are an archipelago made up by the summits of 15 volcanic mountains in the north-western Pacific Ocean between the 12th and 21st parallels north and along the 145th meridian east....
  • Philippines
    Philippines

    The Philippines, officially known as the Republic of the Philippines, is a country in Southeast Asia with Manila as its capital city. It comprises 7,107 islands in the western Pacific Ocean....
  • Tonga
    Tonga

    The Kingdom of Tonga in the south Pacific Ocean comprises an archipelago of 171 islands, 48 of them inhabited, stretching over a distance of about 800 kilometres in a north-south line....
     and Kermadec Islands
    Kermadec Islands

    The Kermadec Islands are an island arc in the South Pacific Ocean. The islands have been part of New Zealand since 1887.The islands lie within 29? to 31.5? south latitude and 178? to 179? west longitude, 800 – 1000 km northeast of New Zealand's North Island, and a similar distance southwest of Tonga....
  • Crete
    Crete

    Crete is the largest of the Greek islands and the List of islands in the Mediterranean largest island in the Mediterranean Sea at 8,336 km? ....
     and Dodecanese
    Dodecanese

    The Dodecanese are a group of 12 larger plus 150 smaller Greece list of islands of Greece in the Aegean Sea, off the southwest coast of Turkey, southward of the island of Samos and northeastward of the island of Crete....
  • Andaman
    Andaman Islands

    The Andaman Islands are a group of archipelago islands in the Bay of Bengal, and are part of the Andaman and Nicobar Islands Union Territory of India....
     and Nicobar Islands
    Nicobar Islands

    The Nicobar Islands are an island chain in the eastern Indian Ocean, and are part of the Union Territory of Andaman and Nicobar Islands, India....
  • Mentawai Islands
    Mentawai Islands

    The Mentawai Islands are a chain of about seventy islands and islets off the western coast of Sumatra in Indonesia. Siberut is the largest of the islands....
  • Sunda Arc
    Sunda Arc

    The Sunda Arc is a volcanic arc that has produced the islands of Sumatra and Java and the Sunda Strait and the Lesser Sunda Islands. A chain of volcanoes forms the topographic spine of these islands....
  • Lesser Sunda Islands
    Lesser Sunda Islands

    The Nusa Tenggara , or Lesser Sunda Islands, are a group of islands in the middle-south part of Maritime Southeast Asia. Together with the Greater Sunda Islands to the west they make up the Sunda Islands....
  • Tanimbar
    Tanimbar Islands

    The Tanimbar Islands, also called Timor Laut, are a group of about 65 islands in the Maluku Provinces of Indonesia of Indonesia, including Fordata, Larat, Maru, Molu, Nuswotar, Selaru, Selu, Seira, Wotap, Wuliaru and Yamdena....
     and Kai Islands
    Kai Islands

    The Kai Islands of Indonesia are in the south-eastern part of the Maluku Islands, in Maluku Provinces of Indonesia....
  • Solomon Islands
    Solomon Islands

    For the group of islands rather than the nation, see Solomon Islands .The Solomon Islands is a country in Melanesia, east of Papua New Guinea, consisting of nearly one thousand islands....
  • South Aegean Volcanic Arc
    South Aegean Volcanic Arc

    The South Aegean Volcanic Arc is chain of volcanic islands in the South Aegean Sea formed by plate tectonics as an oceanic tectonic plate subducts under another tectonic plate which produces magma....
  • Lesser Antilles
    Lesser Antilles

    The Lesser Antilles, also known as the Caribbees, are part of the Antilles, which together with the Bahamas, the Turks and Caicos Islands, and Greater Antilles form the West Indies....
    , including the Leeward Antilles
    Leeward Antilles

    The Leeward Antilles are a chain of islands in the Caribbean ? specifically, the southerly islands of the Lesser Antilles along the southeastern fringe of the Caribbean Sea, just north of the Venezuelan coast of the South American mainland....
  • Scotia Arc
    Scotia Arc

    Scotia Arc is the island arc system forming the north, east and south border of Scotia Sea. The arc comprises submarine ridges and the island groups of South Orkney Islands, South Sandwich Islands, Clerke Rocks, South Georgia, Shag Rocks, South Georgia, Isla de los Estados, and Burdwood Bank linking the mountains of Antarctic Peninsula to t...
    :
    • South Sandwich Islands
  • Mascarene Islands
    Mascarene Islands

    The Mascarene Islands is a group of islands in the Indian Ocean east of Madagascar comprising Mauritius, R?union, Rodrigues , Cargados Carajos shoals, plus the former islands of the Saya de Malha Bank, Nazareth Bank and Soudan Banks banks....


Ancient Island arcs
  • Insular Islands
    Insular Islands

    The Insular Islands were a giant chain of active volcanic islands somewhere in the Pacific Ocean during the Cretaceous time that rode on top a microplate called the Insular Plate, beginning around 130 million years ago....
  • Intermontane Islands
    Intermontane Islands

    The Intermontane Islands were a giant chain of active volcanic islands somewhere out in the Pacific Ocean during the Triassic time beginning around 245 million years ago....
  • Sakhalin island arc
    Sakhalin island arc

    Sakhalin island arc is an ancient volcanic arc dating from the Early Miocene. The arc was a result of the Okhotsk Plate subducting beneath the Eurasian plate in the convergence zone....


See also

  • Back-arc basin
    Back-arc basin

    Back-arc basins are geologic features, submarine basins associated with island arcs and subduction zones.They are found at some convergent boundary, presently concentrated in the Western Pacific ocean....
  • Volcanic belt
    Volcanic belt

    A volcanic belt is a large volcano active region. Other terms are used for smaller areas of activity, such as volcanic fields. Volcanic belts are found above zones of unusually high temperature where magma is created by partial melting of solid material in the Earth's crust and upper mantle ....