Katmai National Park and Preserve is a United States national park and preserve in southwest Alaska, notable for the Valley of Ten Thousand Smokes and for its brown bears. The park and preserve encompass 4,093,077 acres, which is between the sizes of Connecticut and New Jersey. Most of the national park is a designated wilderness area. The park is named after Mount Katmai, its centerpiece stratovolcano. The park is located on the Alaska Peninsula, across from Kodiak Island, with headquarters in nearby King Salmon, about 290 miles (470 km) southwest of Anchorage. The area was first designated a national monument in 1918 to protect the area around the major 1912 volcanic eruption of Novarupta, which formed the Valley of Ten Thousand Smokes, a 40-square-mile (100 km2), 100-to-700-foot-deep pyroclastic flow. The park includes as many as 18 individual volcanoes, seven of which have been active since 1900.
The Alaska Peninsula is a peninsula extending about 497 mi (800 km) 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.
Redoubt Volcano, or Mount Redoubt, is an active stratovolcano in the largely volcanic Aleutian Range of the U.S. state of Alaska. Located at the head of the Chigmit Mountains subrange in Lake Clark National Park and Preserve, the mountain is just west of Cook Inlet, in the Kenai Peninsula Borough about 110 miles (180 km) southwest of Anchorage. At 10,197 feet (3,108 m), in just over 5 miles (8.0 km) Mount Redoubt attains 9,150 feet (2,790 m) of prominence over its surrounding terrain. It is the highest summit in the Aleutian Range. In 1976, Redoubt Volcano was designated as a National Natural Landmark by the National Park Service.
Shishaldin Volcano, or Mount Shishaldin, is one of six active volcanoes on Unimak Island in eastern the Aleutian Islands of Alaska. It is the highest mountain peak of the Aleutian Islands, rising to a height of 9,373 ft above sea level. Shishaldin's magma supply is generated via flux melting above the Aleutian Trench, where the Pacific Plate subducts beneath the North American Plate. Due to its remote location and frequently inclement weather, the Alaska Volcano Observatory (AVO) monitors the volcano remotely via satellite and a seismic network deployed in 1997. Shishaldin is one of the most active volcanoes in the Aleutian Islands, with 40 confirmed eruptions in the last 11,700 years. Notably, Shishaldin produced a sub-Plinian eruption in 1999.
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 geologist G. C. Martin. The Alaska Volcano Observatory currently rates Douglas as Level of Concern Color Code Not Assigned.
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.
The Ukinrek maars are two volcanic craters on the north side of the Aleutian Range in Alaska that were formed by a phreatomagmatic eruption in 1977. The maars are 1.5 km south of Becharof Lake and 12 km northwest of Peulik Volcano, on a low area of the range, bordering the Bering Sea. The western of the two is elliptical in shape and up to 170 m in diameter and 35 m deep. The other lies 600 m to the east and is circular and up to 300 m in diameter and 70 m deep. The east maar has a 49 m-high lava dome within its crater lake.
Mount Chiginagak is a stratovolcano on the Alaska Peninsula, located about 15 km northwest of Chiginagak Bay.
Mount Pavlof or Pavlof Volcano is a stratovolcano of the Aleutian Range on the Alaska Peninsula. It has been one of the most active volcanoes in the United States since 1980, with eruptions recorded in 1980, 1981, 1983, 1986–1988, 1996–1997, 2007, 2013, twice in 2014, 2016, and again in 2021-2022. It is not currently erupting (as of October 15, 2024). The most common lava type here is basaltic andesite and the 2013-2014 lavas contained approximately 53 wt.% SiO2. The volcano is monitored by the Alaska Volcano Observatory- 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). With a threat score of 95, the threat from future eruptions is considered to be high; much of this threat comes from the possibility of disruption of nearby air routes by large releases of ash. The mountain shares a name with the nearby Pavlof Sister, which is thought to have last erupted from 1762 to 1786, although this period of activity is sometimes attributed to Pavlof volcano instead.
Westdahl Peak, also known as Westdahl Volcano or Mount Westdahl, is a stratovolcano of the Aleutian Range, in the U.S. state of Alaska. The volcano last erupted from November 29, 1991, to January 15, 1992.
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.
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.
Kanaga Volcano, or Mount 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 fumarolic activity.
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.
Mother Goose Lake is a 6.4 mile long lake located at head of King Salmon River, on the Alaska Peninsula, 21 miles south of Ugashik, Aleutian Range. It was named in 1923 by R. H. Sargent, USGS, as "suggested by its goose-like shape." According to Sargent, the local name was King gautham giri Lake. The lake lies entirely within the Alaska Peninsula National Wildlife Refuge.
Southwest Alaska is a region of the U.S. state of Alaska. The area is not exactly defined by any governmental administrative region(s); nor does it always have a clear geographic boundary.
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.
The Aleutian Arc is a large volcanic arc of islands extending from the Southwest tip of the U.S. state of Alaska to the Kamchatka Peninsula of the Russian Federation.
