Novarupta (meaning "newly erupted"
in
Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
) is a
volcano
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface.
On Earth, volcanoes are most often found where tectonic plates are ...
that was formed in 1912, located 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 mainland of Alaska and ending in the Aleutian Islands. The ...
on a slope of
Trident Volcano
Trident Volcano is an eroded volcanic complex on the Alaska Peninsula in Katmai National Park, Alaska. Up to 23 domes comprise the complex stratovolcano, with the greatest elevation of . The most recent major activity produced a dome in an amphi ...
in
Katmai National Park and Preserve
Katmai National Park and Preserve is an American 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 , which is between the sizes of Connecticut ...
, about 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 Ma ...
. Formed during the largest volcanic eruption of the 20th century, Novarupta released 30 times the volume of
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
of the
1980 eruption of Mount St. Helens.
Eruption of 1912
The 1912 eruption that formed Novarupta was the largest to occur during the 20th century. It began on June 6, 1912, and culminated in a series of violent eruptions. Rated a 6 on the
Volcanic Explosivity Index,
[
] the 60-hour-long eruption expelled of ash, thirty times as much as the
1980 eruption of Mount St. Helens.
[
][
] The erupted magma of
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
,
dacite
Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. ...
, and
andesite
Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...
[Wood, C.A. and Kienle, J. (editors) (1990) ''Volcanoes of North America: United States and Canada'', Cambridge, Cambridge University Press, , page 70.] resulted in more than of
air fall tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...
and approximately of
pyroclastic ash-flow tuff.
[
] During the 20th century, only the
1991 eruption of Mount Pinatubo in the
Philippines
The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no),
* bik, Republika kan Filipinas
* ceb, Republika sa Pilipinas
* cbk, República de Filipinas
* hil, Republ ...
and the 1902 eruption of
Santa María in
Guatemala
Guatemala ( ; ), officially the Republic of Guatemala ( es, República de Guatemala, links=no), is a country in Central America. It is bordered to the north and west by Mexico; to the northeast by Belize and the Caribbean; to the east by H ...
were of comparable magnitude;
Mount Pinatubo
Mount Pinatubo is an active stratovolcano in the Zambales Mountains, located on the tripoint boundary of the Philippine provinces of Zambales, Tarlac and Pampanga, all in Central Luzon on the northern island of Luzon. Its eruptive history w ...
ejected of
tephra
Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism.
Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...
, and Santa María just slightly less.
At least two larger eruptions occurred in the
Dutch East Indies
The Dutch East Indies, also known as the Netherlands East Indies ( nl, Nederlands(ch)-Indië; ), was a Dutch colony consisting of what is now Indonesia. It was formed from the nationalised trading posts of the Dutch East India Company, which ...
(now
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
) during the 19th century: the
1815 eruption of
Tambora ( of tephra)
[
] and the
1883 eruption of Krakatoa
The 1883 eruption of Krakatoa ( id, Letusan Krakatau 1883) in the Sunda Strait occurred from 20 May until 21 October 1883, peaking in the late morning hours of 27 August when over 70% of the island of Krakatoa and its surrounding archipelago w ...
(
of tephra).
The Novarupta eruption occurred about from the peak of
Mount Katmai Volcano and below the post-eruption Mount Katmai summit. During the eruption a large quantity of
magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...
erupted from beneath the Mount Katmai area, resulting in the formation of a wide, funnel-shaped vent and the collapse of Mount Katmai's summit, creating a deep,
caldera
A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...
.
[
]
The eruption ended with the extrusion of a
lava dome
In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...
of
rhyolite
Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...
that
plugged the vent. The high and wide dome it created forms what is now referred to as Novarupta.
Despite the magnitude of the eruption, no deaths directly resulted.
[
] Eyewitness accounts from people located downwind in the path of a thick ash cloud described the gradual lowering of visibility to next to nothing.
Ash threatened to contaminate drinking water and destroyed food resources, but the
Alaska Native
Alaska Natives (also known as Alaskan Natives, Native Alaskans, Indigenous Alaskans, Aboriginal Alaskans or First Alaskans) are the indigenous peoples of Alaska and include Iñupiat, Yupik, Aleut, Eyak, Tlingit, Haida, Tsimshian, and a numbe ...
s were aided in their survival by
traditional knowledge
Traditional knowledge (TK), indigenous knowledge (IK) and local knowledge generally refer to knowledge systems embedded in the cultural traditions of regional, indigenous, or local communities. According to the World Intellectual Property Organ ...
passed down through generations from previous eruptions. However, the Native villages experiencing the heaviest ash falls were abandoned and the inhabitants relocated.
Valley of Ten Thousand Smokes
Pyroclastic flows
A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...
from the eruption formed the
Valley of Ten Thousand Smokes
The Valley of Ten Thousand Smokes is a valley within Katmai National Park and Preserve in Alaska which is filled with ash flow from the eruption of Novarupta on June 6–8, 1912.
Following the eruption, thousands of fumaroles vented steam fro ...
, named by botanist
Robert F. Griggs, who explored the volcano's aftermath for the
National Geographic Society
The National Geographic Society (NGS), headquartered in Washington, D.C., United States, is one of the largest non-profit scientific and educational organizations in the world.
Founded in 1888, its interests include geography, archaeology, and ...
in 1916.
[
]
The eruption that formed the Valley of Ten Thousand Smokes is one of the few in recorded history to have produced
welded tuff
Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...
, producing numerous
fumaroles
A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...
that persisted for 15 years.
[
]
Katmai National Park
Established as a
National Park & Preserve in 1980, Katmai is located on the Alaska Peninsula, across from Kodiak Island, with headquarters in nearby
King Salmon
The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus '' Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other v ...
, about southwest of Anchorage. The area was originally designated a
National Monument
A national monument is a monument constructed in order to commemorate something of importance to national heritage, such as a country's founding, independence, war, or the life and death of a historical figure.
The term may also refer to a spec ...
in 1918 to protect the area around the 1912 eruption of Novarupta and the , deep, pyroclastic flow of the Valley of Ten Thousand Smokes.
[
]
See also
*
* Timeline of volcanism on Earth">/[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu ...
* Timeline of volcanism on Earth
* Parícutin, a cinder cone volcano in Mexico whose emergence could be fully observed.