Iliamna Volcano, or Mount Iliamna ( Dena'ina: ''Ch’naqał’in''; Sugpiaq: ''Puyulek''), is a

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such a ...

-covered

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

in the largely volcanic

Aleutian Range The Aleutian Range is a major mountain range located in southwest Alaska. It extends from Chakachamna Lake (80 miles/130 km southwest of Anchorage) to Unimak Island, which is at the tip of the Alaska Peninsula. It includes all of the mountain ...

in southwest Alaska. Located in the Chigmit Mountain subrange in Lake Clark National Park and Preserve, the volcano lies approximately southwest of

Anchorage Anchorage () is the largest city in the U.S. state of Alaska by population. With a population of 291,247 in 2020, it contains nearly 40% of the state's population. The Anchorage metropolitan area, which includes Anchorage and the neighboring ...

on the west side of lower

Cook Inlet Cook Inlet ( tfn, Tikahtnu; Sugpiaq: ''Cungaaciq'') stretches from the Gulf of Alaska to Anchorage in south-central Alaska. Cook Inlet branches into the Knik Arm and Turnagain Arm at its northern end, almost surrounding Anchorage. On its so ...

. It is the 25th most prominent peak in the United States.Alaska Volcano Observatory, Volcano Information - Iliamna
Retrieved Dec. 16, 2022. Mount Iliamna in July 2015

The volcano's glaciers have extensively altered its profile, cutting, deep and creating steep cliffs and cirques. A ridge extends south from the main body of the mountain, with North Twin and South Twin peaks along its length. There is no summit crater, only a zone of fumaroles just south of the summit at the top of large collapse zone at the head of Red Glacier, which exposes a cross section of the mountain.

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

eruptive activity from Iliamna is little known, but

radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was de ...

seems to indicate at least a few eruptions, all before the

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

an settlement of Alaska. Prehistoric eruptions have been dated to 5050 and 2050 BCE ( VEI-4), 450 BCE and 1650. Historically observed eruptions took place in 1867 (VEI-2) and 1876 (VEI-3), with unconfirmed eruptions in 1933, 1947, 1952 and 1953. Fumaroles located at about elevation on the eastern flank produce nearly constant plumes of steam and minor amounts of

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formul ...

ous gases. These plumes are quite vigorous and have resulted in numerous pilot reports and early historical accounts of "eruptions" at Iliamna Volcano. Earthquake swarms and elevated seismicity and gas emissions were reported in 1996-97 and 2011–13. Iliamna was ranked as a high-threat volcano by the U.S. Geological Survey in 2005 and 2018. The 2018 assessment ranked Iliamna as the 20th most hazardous volcano in the United States, up from 22nd, with an aviation threat score of 34 and an overall score of 115, the second highest of the "high threat" category. Major glaciers radiate from the summit of Iliamna, including Red Glacier, Tuxedni Glacier, Lateral Glacier and Umbrella Glacier. Iliamna was first ascended in 1959. It was designated a

National Natural Landmark The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best ...

in 1976.

References

External links

Iliamna Volcano
at the National Park Service Volcanoes of Kenai Peninsula Borough, Alaska Stratovolcanoes of the United States Volcanoes of Alaska Lake Clark National Park and Preserve Aleutian Range Mountains of Alaska Mountains of Kenai Peninsula Borough, Alaska North American 3000 m summits National Natural Landmarks in Alaska Holocene stratovolcanoes {{KenaiPeninsulaAK-geo-stub

See also

References

External links