| Anvil Peak | |
|---|---|
  Anvil Peak Location on the Semisopochnoi Island in Alaska | |
| Highest point | |
| Elevation | 1,221 m (4,006 ft) |
| Coordinates | 51°59′10″N179°36′11″E / 51.98605°N 179.60313°E |
| Geography | |
| Location | Aleutian Islands, Alaska, United States |
| Geology | |
| Mountain type | Volcano |
Anvil Peak is a cone volcano located in Aleutian Islands, Alaska, United States.
The volcano was originally named in 1951, on a map by the United States Geological Survey. Its name was taken after a plateau located on the northern side of the volcano's main summit, taking the appearance of an anvil. [1]
Anvil Peak is located on Semisopochnoi Island, in the Rat Islands of the western Aleutian Islands. It is one of the seven hills with a summit crater on the island. [2] It is the highest point on the island as well as the highest point on all of the Rat Islands. [3] It is located further north than any of the other hills on the island, [2] taking up a large amount of the northern part of the island. [4] The volcano is located 161 miles (259 km) away from Atka, 237 miles (381 km) from Shemya, and 263 miles (423 km) from Attu. [5]
Anvil Peak has two summits, which are both volcanic cones. The larger main summit is 1,221 metres (4,006 ft) tall, [5] making it the highest point on the island. This summit is surrounded by ravines, which contain snow at certain times of the year. The peak is part of the old rim of a crater on the volcano, which had been slightly lowered due to erosion. [6]
A plateau is located north of this summit, which is what the volcano was named after. [1] The plateau is about 1,200 feet (370 m) wide and is almost completely flat. Six lava flows, about 20 feet (6.1 m) wide each, are located beneath this area. These flows are visible on all except one of the sides of the cliffs holding up the flat area, and had previously been located inside of the crater on the volcano. The other summit is located southwest of the main summit, and is slightly shorter. [6]
It is not known exactly when Anvil Peak first formed, but it is believed to have formed after Mount Cerberus. [7] According to the Global Volcanism Program of the Smithsonian Institution, its formation occurred during the late Pleistocene epoch. [4] It has not erupted in recent times; it is thought that its last activity was probably thousands of years ago. [7] Anvil Peak has experienced deep erosion, more so than the other cones on the islands, which is partially due to its height. [6]
Mount Spurr (Dena'ina: K'idazq'eni) is a stratovolcano in the Aleutian Arc of Alaska, named after United States Geological Survey geologist and explorer Josiah Edward Spurr, who led an expedition to the area in 1898. The Alaska Volcano Observatory (AVO) currently rates Mount Spurr as Level of Concern Color Code Green. The mountain is known aboriginally by the Dena'ina Athabascan name K'idazq'eni, literally 'that which is burning inside'.
Shishaldin Volcano, or Mount Shishaldin, is a moderately active volcano on Unimak Island in the Aleutian Islands chain of Alaska in the United States. It is the highest mountain peak of the Aleutian Islands and rises about 10,000m from the bottom of the Aleutian Trench 140 miles south of the volcano. The volcano's topographic contour lines are nearly perfect circles above 6,500 feet (1,981 m). The lower north and south slopes are somewhat steeper than the lower eastern and western slopes. Only on the volcano's west flank between about 3500 to 6500 ft are small areas of rough topography which are remnants of an older collapsed volcano upon which Shishaldin is built. The volcano is the westernmost of three large stratovolcanoes along an east–west line in the eastern half of Unimak Island.
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 fumaroles persist in a summit crater and along the upper southwest flank. The fumaroles on the southwest flank are the hottest, and some of the flank fumaroles can roar so loudly that they can be heard from the valley floor. The slopes of Mount Griggs are heavily mantled by fallout from the 1912 eruption of Novarupta volcano. The summit consists of three concentric craters, the lowest and largest of which contains a recent summit cone topped by two craters. The volume of the volcanic edifice is estimated at 25 cubic kilometers (6.0 cu mi). Isotopic analysis indicates that the source of Griggs' magma is distinct from the other Katmai volcanoes.
Mount Emmons is a post-caldera stratovolcano within the Emmons Lake caldera on the Alaska Peninsula within the Lake and Peninsula Borough, Alaska, United States.
Mount Akutan, officially Akutan Peak, is a stratovolcano in the Aleutian Islands of Alaska. Akutan Peak, at 4,275 feet (1,303 m), 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 activity has originated from a large cinder cone on the NE part of the caldera. It has been the source of frequent explosive eruptions with occasional lava effusion that blankets the caldera floor. A lava flow in 1978 traveled through a narrow breach in the north caldera rim to within 2 km of the coast. A small lake occupies part of the caldera floor. Two volcanic centers are located on the NW flank: Lava Peak is of Pleistocene age; and, a cinder cone lower on the flank which produced a lava flow in 1852 that extended the shoreline of the island and forms Lava Point. An older, mostly buried caldera seems to have formed in Pleistocene or Holocene time, while the current caldera formed in a VEI-5 eruption c. 340 AD. AVO has recorded 33 confirmed eruptions at Akutan, making it the volcano with the most eruptions in Alaska.
The 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 2,036 meters (6,680 ft), its summit is the highest point on the island. Makushin is one of the most active among the 52 historically active volcanoes of Alaska. It has erupted at least two dozen times over the past several thousand years, with the last eruption occurring in 1995.
Mount 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. The base of the volcano is around 10 km (6 mi) wide, steepening from about 15 degrees at 300 m (980 ft) altitude to around 30 degrees near the summit. Some glacial tongues have cut through narrow canyons up to 120 m (390 ft) deep, due to ice filling the crater and extending down the north and east flanks of the cone. Vsevidof's most recent eruption was caused by an earthquake on March 9, 1957. The eruption began March 11, and ended the next day.
Mount Cleveland is a nearly symmetrical stratovolcano on the western end of Chuginadak Island, which is part of the Islands of Four Mountains just west of Umnak Island in the Fox Islands of the Aleutian Islands of Alaska. Mt. Cleveland is 5,675 ft (1,730 m) high, and one of the most active of the 75 or more volcanoes in the larger Aleutian Arc. Aleutian natives named the island after their fire goddess, Chuginadak, who they believed inhabited the volcano. In 1894 a team from the United States Coast and Geodetic Survey visited the island and gave Mount Cleveland its current name, after then-president Grover Cleveland.
The 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. The cone, about 5.8 km in basal diameter and topped by a 0.4 km wide summit crater, appears on synthetic-aperture radar imagery to be built upon a 300+ meter high, east-west trending arcuate ridge. Extensions of that ridge on the southwest and east sides of the island indicate an older caldera approximately 6 km in diameter and open to the sea on the south side. No hot springs or fumaroles have been reported from Amukta. Sekora reports the presence of a cinder cone near the northeastern shore of the island.
Iliamna Volcano, or Mount Iliamna, is a glacier-covered stratovolcano in the largely volcanic Aleutian Range in southwest Alaska. Located in the Chigmit Mountain subrange in Lake Clark National Park and Preserve, the 10,016-foot (3,053 m) volcano lies approximately 134 miles (215 km) southwest of Anchorage on the west side of lower Cook Inlet. It is the 25th most prominent peak in the United States.
Korovin Volcano is one of four volcanic centers of the Atka Volcanic Complex, located near the town of Atka on the northeast part of Atka Island in the Aleutian Islands chain, Alaska, United States. At 5,030 feet (1,530 m), Korovin is the highest point on the island.
Semisopochnoi Island or Unyak 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 Young. It has a land area of 85.558 square miles, measuring 11 miles (18 km) in length and 12 miles (20 km) in width.
Little Sitkin Island is a volcanic island in the Rat Islands archipelago of the Western Aleutian Islands, Alaska, about 3 miles (4.8 km) east of Davidof Island. Great Sitkin Island lies 185 miles (298 km) further east in the Andreanof Islands.
The Alaska Volcano Observatory (AVO) is a joint program of the United States Geological Survey (USGS), the Geophysical Institute of the University of Alaska Fairbanks (UAFGI), and the State of Alaska Division of Geological and Geophysical Surveys (ADGGS). AVO was formed in 1988, and uses federal, state, and university resources to monitor and study Alaska's volcanology, hazardous volcanoes, to predict and record eruptive activity, and to mitigate volcanic hazards to life and property. The Observatory website allows users to monitor active volcanoes, with seismographs and webcameras that update regularly. AVO now monitors more than 20 volcanoes in Cook Inlet, which is close to Alaskan population centers, and the Aleutian Arc due to the hazard that plumes of ash pose to aviation.
Bobrof Island is one of the Andreanof Islands subgroup of the Aleutian Islands in southwestern Alaska, United States. Bobrof Island is a small, uninhabited island about 9 miles (14 km) north and west of Kanaga Island, and 7 miles (11 km) northeast of Cape Sudak on Tanaga Island. Bobrof Island is 2.6 miles (4.2 km) long and 1.8 miles (2.9 km) wide with an area of 3 square miles (7.8 km2), and consists primarily of the 2,421-foot (738 m) high Bobrof Volcano. The volcanic crater, or cone, has been heavily dissected. Underwater deposits adjacent to the island's northeast flank suggest an immense debris-avalanche has taken place.
Mount Gareloi, or Gareloi Volcano, is a stratovolcano in the Aleutian Islands of Alaska, United States, about 1,259 miles (2,026 km) 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.
Amak Volcano is a basaltic andesite stratovolcano in the Aleutian Islands of Alaska, United States, 618 miles (995 km) from Anchorage. It is located on the eponymous island, 31 miles (50 km) from Frosty Volcano and near the edge of the Alaskan Peninsula's western flank. Only boats are allowed to access the island with a certain permit.
Segula Volcano lies 1,228 miles (1,976 km) westward of Anchorage on the Segula Island in the Aleutian Islands of Alaska. An inactive stratovolcano, it has not produced any historical eruptions, while barely eroded deposits on the flanks suggest that activity took place at the volcano as late as a couple of hundred years ago.
The volcanic history of the Northern Cordilleran Volcanic Province presents a record of volcanic activity in northwestern British Columbia, central Yukon and the U.S. state of easternmost Alaska. The volcanic activity lies in the northern part of the Western Cordillera of the Pacific Northwest region of North America. Extensional cracking of the North American Plate in this part of North America has existed for millions of years. Continuation of this continental rifting has fed scores of volcanoes throughout the Northern Cordilleran Volcanic Province over at least the past 20 million years and occasionally continued into geologically recent times.