The Aleutian Arc is a large volcanic arc in the U.S. state of

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...

. It consists of a number of active and dormant volcanoes that have formed as a result of

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...

along the Aleutian Trench. Although taking its name from the Aleutian Islands, this term is a geologic grouping rather than a geographic one, and the Aleutian Arc extends through the

Alaska Peninsula The Alaska Peninsula (also called Aleut Peninsula or Aleutian Peninsula, ale, Alasxix̂; Sugpiaq: ''Aluuwiq'', ''Al'uwiq'') is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The ...

following the Aleutian Range to the

Aleutian Islands The Aleutian Islands (; ; ale, Unangam Tanangin,”Land of the Aleuts", possibly from Chukchi ''aliat'', "island"), also called the Aleut Islands or Aleutic Islands and known before 1867 as the Catherine Archipelago, are a chain of 14 large v ...

. The Aleutian Arc reflects subduction of the

Pacific Plate The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and I ...

beneath the

North American Plate The North American Plate is a tectonic plate covering most of North America, Cuba, the Bahamas, extreme northeastern Asia, and parts of Iceland and the Azores. With an area of , it is the Earth's second largest tectonic plate, behind the Paci ...

. It extends from the

Kamchatka Peninsula The Kamchatka Peninsula (russian: полуостров Камчатка, Poluostrov Kamchatka, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and w ...

in the west to the Gulf of Alaska in the east. Unimak Pass at the southwestern end of the Alaska Peninsula marks the eastward transition from an intra-oceanic in the west to a continental arc in the east. Due to the arcuate geometry of the trench, the relative velocity vector changes from almost trench-normal in the Gulf of Alaska to almost trench-parallel in the west. Along the oceanic part of the subduction zone, convergence varies from per year to the north-northwest in the east to per year towards the northwest in the west.

Volcanoes

Volcanoes within this arc include: * Mount Adagdak * Mount Akutan *

Mount Amak Mount is often used as part of the name of specific mountains, e.g. Mount Everest. Mount or Mounts may also refer to: Places * Mount, Cornwall, a village in Warleggan parish, England * Mount, Perranzabuloe, a hamlet in Perranzabuloe parish, C ...

* Mount Amukta *

Mount Aniakchak Mount Aniakchak (russian: Аниакчак) is a 3,700-year-old volcanic caldera approximately in diameter, located in the Aleutian Range of Alaska, United States. Although a stratovolcano by composition, the pre-existing mountain collapsed in ...

* Augustine Volcano * Black Peak *

Bogoslof Island Bogoslof Island or Agasagook Island ( ale, Aĝasaaĝux̂) is the summit of a submarine stratovolcano at the south edge of the Bering Sea, northwest of Unalaska Island of the Aleutian Island chain. It has a land area of and is uninhabited. The p ...

Mount Carlisle Mount Carlisle is a stratovolcano in Alaska which forms part of the 5 mile (8 km) wide Carlisle Island, one of the Islands of Four Mountains which, in turn, form part of the central Aleutian Islands. Despite its modest summit elevation, a ...

* Mount Chiginagak * Cleveland Volcano *

Cold Bay Volcano Frosty Peak Volcano, also known as Mt. Frosty, Frosty Volcano, or Cold Bay Volcano, is a 6,299 ft (1,920 m) stratovolcano at the southwest end of the Alaska Peninsula in the U.S. state of Alaska. History Frosty Peak is the tallest ...

* Mount Dana * Davidof Volcano * Mount Denison * Devils Desk * Mount Douglas * Mount Dutton * Mount Emmons *

Fourpeaked Mountain Fourpeaked Volcano is an active stratovolcano in the U.S. state of Alaska. The Alaska Volcano Observatory rates Fourpeaked Volcano as Aviation Alert Level Green and Volcanic-alert Level Normal. It is nearly completely covered by Fourpeaked Gla ...

* Mount Frosty * Gareloi Volcano * Great Sitkin * Mount Gilbert *

Mount Griggs Mount Griggs, formerly known as Knife Peak Volcano, is a stratovolcano, which lies 10 km behind the volcanic arc defined by other Katmai group volcanoes. Although no historic eruptions have been reported from Mount Griggs, vigorously active ...

Hayes Volcano Hayes Volcano is a stratovolcano in southwestern Matanuska-Susitna Borough, Alaska, 135 km northwest of Anchorage, that was not discovered until 1975. It is responsible for a series of six major tephra layers in the Cook Inlet region of Alas ...

* Mount Iliamna *

Isanotski Peaks Isanotski Peaks or Isanotski Volcano, known locally as "Ragged Jack", is a multipeaked mountain on Unimak Island, the easternmost Aleutian Island in Alaska, United States. It is an old, highly dissected stratovolcano, lying about 10 miles (16&nbs ...

Mount Kaguyak Mount Kaguyak is a stratovolcano located in the northeastern part of the Katmai National Park and Preserve in the U.S. state of Alaska. The wide caldera is filled by a more than 180 m deep crater lake. The surface of the crater lake lies abo ...

* Mount Kanaga * Kasatochi Island * Mount Katmai * Mount Kialagvik *

Kiska Kiska ( ale, Qisxa, russian: Кыска) is one of the Rat Islands, a group of the Aleutian Islands of Alaska. It is about long and varies in width from . It is part of Aleutian Islands Wilderness and as such, special permission is requir ...

* Korovin Volcano * Mount Kukak * Mount Kupreanof *

Mount Mageik Mount Mageik is a stratovolcano on the Alaska Peninsula. It has no confirmed historical eruptions (one in 1946 is now deemed questionable), but its youngest eruptive products are apparently Holocene in age (8750 to 500 BCE). A young crater lies ...

Makushin Volcano The Makushin Volcano (also known as Mount Makushin) is an ice-covered stratovolcano located on Unalaska Island in the Aleutian Islands of the U.S. state of Alaska. With an elevation of , its summit is the highest point on the island. Makushin is ...

* Mount Martin * Novarupta * Nunivak Island * Mount Okmok * Mount Pavlof *

Pavlof Sister Pavlof Sister is a stratovolcano on the Alaska Peninsula The Alaska Peninsula (also called Aleut Peninsula or Aleutian Peninsula, ale, Alasxix̂; Sugpiaq: ''Aluuwiq'', ''Al'uwiq'') is a peninsula extending about to the southwest from the m ...

Pogromni Volcano Pogromni Volcano is a stratovolcano on Unimak Island in the Aleutian Islands. Near it are 5 cinder cones, and a mountain called Pogromni's Sister. Pogromni is old and eroded with a single glacier on its flank and base. Eruptions have been attrib ...

* Mount Recheshnoi * Mount Redoubt * Saint Paul Island * Mount Seguam *

Segula Island Segula Island ( ale, Chiĝulax̂) is an island in the Rat Islands archipelago of the western Aleutian Islands, Alaska. It consists of a Holocene stratovolcano, called Segula Volcano. Segula Island is three to four miles in diameter, and is lo ...

* Semisopochnoi Island * Mount Shishaldin * Snowy Mountain * Mount Spurr * Mount Steller * Tanaga * Trident Volcano * Ugashik-Peulik * Mount Veniaminof *

Mount Vsevidof Mount Vsevidof ( or ; russian: Вулкан Всевидова) is a stratovolcano in the U.S. state of Alaska. Its summit is the highest point on Umnak Island, one of the eastern Aleutian Islands. Its symmetrical cone rises abruptly from its su ...

* Mount Westdahl * Yantarni Volcano

References

External links

Geoprisms.org: Aleutian Arc
Aleutian Islands Aleutian Range Volcanic arcs Volcanism of Alaska {{Volcanology-stub