Aleutian Arc
Encyclopedia
Volcanic arc
A volcanic arc is a chain of volcanoes positioned in an arc shape as seen from above. Offshore volcanoes form islands, resulting in a volcanic island arc. Generally they result from the subduction of an oceanic tectonic plate under another tectonic plate, and often parallel an oceanic trench...
in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
of Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...
. It consists of a number of active and dormant volcanoes that have formed as a result of subduction
Subduction
In geology, subduction is the process that takes place at convergent boundaries by which one tectonic plate moves under another tectonic plate, sinking into the Earth's mantle, as the plates converge. These 3D regions of mantle downwellings are known as "Subduction Zones"...
along the Aleutian Trench
Aleutian Trench
The Aleutian Trench is a subduction zone and oceanic trench which runs along the southern coastline of Alaska and the adjacent waters of northeastern Siberia off the coast of Kamchatka Peninsula. It is classified as a "marginal trench" in the east as it runs along the margin of the continent, and...
. Although taking its name from the Aleutian Islands, this term is a geologic grouping rather than a geographic one, and the Aleutian Arc extends from the Alaska Peninsula
Alaska Peninsula
The Alaska Peninsula is a peninsula extending about to the southwest from the mainland of Alaska and ending in the Aleutian Islands. The peninsula separates the Pacific Ocean from Bristol Bay, an arm of the Bering Sea....
to the Aleutian Islands.
The Aleutian arc reflects subduction of the Pacific plate
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At 103 million square kilometres, it is the largest tectonic plate....
beneath the North American plate
North American Plate
The North American Plate is a tectonic plate covering most of North America, Greenland, Cuba, Bahamas, and parts of Siberia, Japan and Iceland. It extends eastward to the Mid-Atlantic Ridge and westward to the Chersky Range in eastern Siberia. The plate includes both continental and oceanic crust...
. It extends 3,000 km from the Kamchatka peninsula in the west to the Gulf of Alaska
Gulf of Alaska
The Gulf of Alaska is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found.The entire shoreline of the Gulf is...
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 6.3 cm/yr to the NNW in the east to 7.4 cm/yr towards the NW in the west (DeMets and Dixon 1999).
Volcanoes
Volcanoes within the volcanic arc include:- Mount AdagdakMount AdagdakMount Adagdak is a Pleistocene age stratovolcano on the northernmost extremity of Adak Island in the Aleutian Islands, Alaska. Located about from Anchorage, the mountain is located about south of Cape Adagdak, for which it was named in 1948 by the United States Geological Survey.John Hunter of...
- Mount AkutanMount AkutanMount Akutan, officially Akutan Peak, is a stratovolcano in the Aleutian Islands of Alaska. Akutan Peak, at , is the highest point on the caldera of the Akutan stratovolcano. Akutan contains a 2 km-wide caldera formed during a major explosive eruption about 1600 years ago. Recent eruptive...
- Mount Amak
- Mount AmuktaMount AmuktaThe undissected stratovolcano of Amukta volcano makes up most of nearly circular, 7.7-km-wide Amukta Island . It is the westernmost of the Islands of Four Mountains chain...
- Mount AniakchakMount AniakchakMount Aniakchak is a 3,700 year old volcanic caldera located in the Aleutian Range of Alaska, United States. The area around the volcano is the Aniakchak National Monument and Preserve, maintained by the National Park Service...
- Augustine VolcanoAugustine VolcanoAugustine Volcano is a Lava Dome Complex on Augustine Island in southwestern Cook Inlet in the Kenai Peninsula Borough of southcentral coastal Alaska, southwest of Anchorage. The Alaska Volcano Observatory currently rates Mount Augustine as Level of Concern Color Code Green for aviation and the...
- Black PeakBlack PeakBlack Peak is a highly eroded stratovolcano comprising a lava dome complex on the Alaska Peninsula of the U.S. state of Alaska. Also called Black Volcano or Sopka Chornaia, the mountain is located within the Lake and Peninsula Borough....
- Bogoslof IslandBogoslof IslandBogoslof Island or Agasagook Island is the summit of a largely submarine stratovolcano located in the Bering Sea in the U.S. state of Alaska, behind the main Aleutian volcanic arc. It has a land area of and is unpopulated. The peak elevation of the island is...
- Mount CarlisleMount CarlisleMount Carlisle is a stratovolcano in Alaska which forms part of the 5 mile wide Carlisle Island, one of the Islands of Four Mountains which, in turn, form part of the central Aleutian Islands....
- Mount ChiginagakMount ChiginagakChiginagak Volcano is a stratovolcano in the Aleutian Islands, located about 15 km NW of Chiginagak Bay.- Eruptive history :An unglaciated lava flow and an overlying pyroclastic-flow deposit extending east from the summit are the most recent products of Chiginagak. They most likely originated...
- Cleveland Volcano
- Cold Bay VolcanoCold Bay VolcanoCold Bay Volcano is a 6,299 ft stratovolcano at the southwest end of the Alaska Peninsula in the U.S. state of Alaska.-Sources:* *...
- Mount DanaMount Dana (Alaska)Mount Dana is a small stratovolcano of the Alaska Peninsula, United States, located northeast of Canoe Bay inlet at the head of Pavlof Bay. It was the source for a major eruption about 3840 years ago that produced a pyroclastic flow that filled valleys south and west of the volcano's crater and...
- Davidof VolcanoDavidof VolcanoDavidof Volcano is an inactive stratovolcano and caldera remnant in the Aleutian Islands of Alaska, USA, from Anchorage. Located on the eponymous island, Davidof is part of the Rat Islands sub-chain...
- Mount DenisonMount DenisonMount Denison is a stratovolcano and one of the highest peaks on the Alaska Peninsula. Discovered in 1923 by Harvard professor Kirtly Mather, the mountain was named for the geologist's alma mater, Denison University....
- Devils DeskDevils DeskDevils Desk is a stratovolcano in Alaska's Katmai National Park, split between the Kodiak Island and Lake and Peninsula boroughs of that U.S. state. Its peak, which is located in Kodiak Island Borough, lies 5,879 feet above sea level. It has an elevation of 6,411 feet.-References:*...
- Mount DouglasMount Douglas (Alaska)Mount Douglas is a stratovolcano located south of Kamishak Bay, near the northeasternmost part of the Alaska Peninsula. It lies in the Katmai National Park and Preserve in Kenai Peninsula Borough. The mountain was officially named in 1906 after nearby Cape Douglas based on a 1904 report by USGS...
- Mount DuttonMount DuttonMount Dutton is a stratovolcano in the Aleutian Range of the U.S. state of Alaska, on the Alaska Peninsula.- Geography :Dutton lies just short of from King Cove, a fishing headquarters for the locality.- Geologic activity :...
- Mount Emmons
- Fourpeaked MountainFourpeaked MountainFourpeaked Mountain also known as Fourpeaked Volcano is an active stratovolcano in Alaska. The Alaska Volcano Observatory currently rates Fourpeaked as Aviation Alert Level Green and Volcanic-alert Level Normal. It is nearly completely covered by Fourpeaked Glacier. It was long a dormant volcano...
- Mount FrostyFrosty VolcanoFrosty or Mt. Frosty is a stratovolcano and the westernmost Holocene volcano of the Alaska Peninsula in Alaska, USA. Frosty is the youngest of the two large volcanic structures of the Cold Bay volcanic complex. It has a summit elevation of . Frosty's last known eruption is unknown...
- Gareloi VolcanoGareloi VolcanoThe Gareloi Volcano is a stratovolcano in the Aleutian Islands of Alaska, USA, about from Anchorage. Gareloi is located on Gareloi Island, and comprises most of its land mass. The island also has two small glaciers which protrude to the northwest and southeast....
- Mount GilbertMount Gilbert (Alaska)Mount Gilbert is a volcano which forms the northern part of Akun Island in the eastern Aleutian Islands, USA. Active fumaroles were documented 1 mi northeast of the summit in the early 1900s.-Sources:* *...
- Mount GriggsMount GriggsMount 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 fumaroles persist in a summit crater and along the...
- Hayes VolcanoHayes VolcanoHayes 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 Alaska...
- Mount IliamnaMount IliamnaMount Iliamna is a glacier-carved stratovolcano located approximately 215 km southwest of Anchorage on the west side of lower Cook Inlet. Holocene eruptive activity from Iliamna is little known, but radiocarbon dating seems to indicate at least a few eruptions, all before the European...
- Isanotski PeaksIsanotski PeaksIsanotski 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 east of Shishaldin Volcano, the highest peak in the...
- Mount KaguyakMount KaguyakMount Kaguyak is a stratovolcano located in the northeastern part of the Katmai National Park in Alaska. The 2.5 km wide caldera is filled by a more than 180 m deep crater lake. The surface of the crater lake lies about 550 m below the rim of the caldera. Postcaldera lava domes form a...
- Mount KanagaMount KanagaMount Kanaga is a stratovolcano at the northern tip of Kanaga Island in the Aleutian Islands, Alaska. It is situated within a caldera, which forms the arcuate Kanaton Ridge south and east of Kanaga. A crater lake occupies part of the SE caldera floor. The summit of Kanaga has a crater with...
- Kasatochi IslandKasatochi IslandKasatochi Island also known as Kasatochi volcano is an active stratovolcano and one of the Andreanof Islands subgroup of the Aleutian Islands of southwestern Alaska, USA.-Geography:...
- Mount KatmaiMount KatmaiMount Katmai is a large stratovolcano on the Alaska Peninsula in southern Alaska, located within Katmai National Park and Preserve. It is about in diameter with a central lake-filled caldera about 3 by 2 mi in area, formed during the Novarupta eruption of 1912. The caldera rim reaches a...
- Mount KialagvikMount KialagvikMount Kialagvik is a small poorly known stratovolcano on the Alaska Peninsula of Alaska, United States....
- KiskaKiskaKiska is an island in the Rat Islands group of the Aleutian Islands of Alaska located at . It is about long and varies in width from - Discovery :...
- Korovin Volcano
- Mount KukakMount KukakMount Kukak is an almost completely ice-covered stratovolcano on the Alaska Peninsula of Alaska, United States. Although the last eruption from Mount Kukak is unknown, it displays vigorous fumarolic activity....
- Mount KupreanofMount KupreanofMount Kupreanof is a stratovolcano on the Alaska Peninsula, United States. It is the largest and the northeasternmost in a group of five volcanoes opposite from Stepovak Bay. Mount Kupreanof displays extremely strong fumarole activity and its latest eruption in 1987 produced minor steam and ash...
- Mount MageikMount MageikMount Mageik is a stratovolcano on the Alaska Peninsula. It has no confirmed historical eruptions , but its youngest eruptive products are apparently Holocene in age...
- Makushin VolcanoMakushin VolcanoThe Makushin Volcano is an ice-covered stratovolcano located on Unalaska Island in the Aleutian Islands of the U.S. state of Alaska. With an elevation of , it's summit is the highest point on the island. Makushin is one of the most active among the 40 volcanoes of Alaska...
- Mount MartinMount Martin (Alaska)Mount Martin is a stratovolcano, located on the Alaska Peninsula, United States. It is one of the volcanoes in the vicinity of the Valley of Ten Thousand Smokes. Although an eruption in 1953 is now considered questionable and no other confirmed eruptive activity has taken place at Mount Martin,...
- NovaruptaNovaruptaNovarupta, meaning "new eruption", is a volcano located on the Alaska Peninsula in Katmai National Park and Preserve, about southwest of Anchorage. Formed in 1912 during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of magma as the 1980 eruption of...
- Nunivak IslandNunivak IslandNunivak Island , the second largest island in the Bering Sea, is a permafrost-covered volcanic island lying about 30 miles offshore from the delta of the Yukon and Kuskokwim rivers in the state of Alaska, at about 60° North latitude...
- Mount OkmokMount OkmokMount Okmok is the highest point on the rim of Okmok Caldera on the northeastern part of Umnak Island in the eastern Aleutian Islands of Alaska, USA. This 5.8 mile wide circular caldera truncates the top of a large shield volcano...
- Mount PavlofMount PavlofPavlof Volcano is a stratovolcano of the Aleutian Range on the Alaska Peninsula. It has been one of the most active in the United States since 1980, with eruptions recorded in 1980, 1981, 1983, 1986–1988, 1996–1997, and an ongoing eruption starting on August 15, 2007 and ending on September 13...
- Pavlof SisterPavlof SisterPavlov Sister is a stratovolcano on the Alaska Peninsula. It is a satellite peak of Mount Pavlof, lying directly northeast. The mountain was named by the USGS in 1929.-Sources:* *...
- Pogromni VolcanoPogromni VolcanoPogromni Volcano is a stratovolcano on Unimak Island in the Aleutian Islands. Near it are 5 cinder cones, and a mountain called Pogromni's Sister....
- Mount RecheshnoiMount RecheshnoiMount Recheshnoi is a heavily eroded stratovolcano located near the center of the SW lobe of Umnak Island in the Aleutian Islands of Alaska....
- Mount RedoubtMount RedoubtMount Redoubt is the name of three mountains:* Mount Redoubt in Alaska, United States* Mount Redoubt in Washington, United States* Redoubt Mountain in Banff National Park, Canada...
- Saint Paul Island
- Mount SeguamMount SeguamMount Seguam is an active stratovolcano on Seguam Island in the Aleutian Islands of Alaska.-Sources:* *...
- Segula IslandSegula IslandSegula Island 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 located about east of Kiska Island...
- Semisopochnoi IslandSemisopochnoi IslandSemisopochnoi Island is part of the Rat Islands group in the western Aleutian Islands of Alaska. The island is uninhabited and provides an important nesting area for maritime birds. The island is of volcanic origin, containing several volcanoes including Mount Cerberus...
- Mount ShishaldinMount ShishaldinMount Shishaldin is a moderately active volcano on Unimak Island in the Aleutian Islands chain of Alaska. It is the tallest mountain in the Aleutian Islands. The most symmetrical cone-shaped glacier-clad large mountain on earth, the volcano's topographic contour lines are nearly perfect circles...
- Snowy MountainSnowy Mountain (Alaska Peninsula, Alaska)Snowy Mountain is a stratovolcano on the Alaska Peninsula of Alaska, United States....
- Mount SpurrMount SpurrMount Spurr is a stratovolcano in the Aleutian Volcanic Arc of Alaska, named after United States Geological Survey geologist and explorer Josiah Edward Spurr, who led an expedition to the area in 1898...
- Mount StellerMount Steller (Aleutian Range)Mount Steller is a stratovolcano in Katmai National Park in Alaska, United States. It is part of the Aleutian Range and is located on the Alaska Peninsula.The mountain was presumably named for the naturalist Georg Wilhelm Steller.-External links:...
- TanagaTanaga (volcano)Tanaga is a 5,924-foot stratovolcano in the Aleutian Range of the U.S. state of Alaska. There have been three known eruptions since 1763. The most recent was in 1914 and produced lava flows.-External links:*...
- Trident Volcano
- Ugashik-PeulikUgashik-PeulikUgashik-Peulik is a stratovolcano in the U.S. state of Alaska. It is located to the south of Becharof Lake in Lake and Peninsula Borough on the Alaska Peninsula. It is part of the Aleutian Range. Its last eruption was in 1814.-Sources:* *...
- Mount VeniaminofMount VeniaminofMount Veniaminof is an active stratovolcano located on the Alaska Peninsula. The Alaska Volcano Observatory currently rates Veniaminof as Aviation Color Code GREEN and Volcano Alert Level NORMAL as of 15:36, 3 June 2009...
- Mount VsevidofMount VsevidofMount Vsevidof 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 surroundings. Its most recent eruption was caused by an earthquake on March 9, 1957...
- Mount WestdahlMount WestdahlMount Westdahl is a stratovolcano in the U.S. state of Alaska. It is located on Unimak Island, near the western tip of the Alaska Peninsula, in the Aleutian Range.- Sources :* *...
- Yantarni VolcanoYantarni VolcanoYantarni Volcano is an andesitic stratovolcano in the U.S. state of Alaska. It is located on the Alaska Peninsula, in the Aleutian Range. It is between Mount Aniakchak and Chiginadak volcanoes. The volcano was not discovered until 1979 due to its remote location, lack of documented historic...