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Fisher Caldera
Fisher Caldera, also known as Mount Fisher and Fisher Volcano, is a large volcanic caldera, measuring about by , located on Unimak Island in the Aleutian Islands of Alaska. Formed by the destructive eruption of an andesitic stratovolcano about 9,100 years ago, it contains three crater lakes, one wide and two others about wide. Small peaks rising and are also present in the caldera. Fisher Caldera is located just from the Mount Westdahl volcano. The largest volcanic eruption on Earth during the Holocene Epoch (the last 11,700 years) occurred at Fisher Caldera in 8700 BCE. References External links * See also * List of volcanic craters in Alaska * List of volcanoes in the United States A list of volcanoes in the United States and its territories. Alaska American Samoa Arizona California Colorado Hawaii / /[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu ... Volcanoes of Alaska Unimak Isl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unimak Island
Unimak Island ( ale, Unimax, russian: Унимак) is the largest island in the Aleutian Islands chain of the U.S. state of Alaska. Geography It is the easternmost island in the Aleutians and, with an area of , the ninth largest island in the United States and the 134th largest island in the world. It is home to Mount Shishaldin, one of the ten most active volcanoes in the world. According to the United States Census Bureau, there were 64 people living on Unimak as of the 2000 census, all of them in the city of False Pass at the eastern end of the island. Cape Lutke is a headland on the island. Cape Pankof is located at the extreme southwest of the island. The Fisher Caldera is a volcanic crater in the west-central part of Unimak. Some characteristics include many volcanic cones and undrained lakes. It is named for Bernard Fisher, a U.S. Geological Survey geologist who was killed in Umnak Pass. Mount Westdahl, in elevation, is a stratovolcano of the Aleutian Range on the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Westdahl
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.Alaska Volcano Observatory, Volcano Information -- Historic eruptions at Westdahl Retrieved Dec. 16, 2022. It is on , near the western tip of the Alaska Peninsula. The volcano has a second summit, called Faris Peak, which is actually the highest point at 5,426 feet (1,654 m). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calderas Of Alaska
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 gone. The ground surface then collapses into the emptied or partially emptied magma chamber, leaving a large depression at the surface (from one to dozens of kilometers in diameter). Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur each century, the formation of a caldera is a rare event, occurring only a few times per century. Only seven caldera-forming collapses are known to have occurred between 1911 and 2016. More recently, a caldera collapse occurred at Kīlauea, Hawaii in 2018. Etymology The term ''caldera'' comes from Spanish ', and Latin ', meaning "co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Aleutians East Borough, Alaska
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 diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanoes Of Alaska
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 diverging or converging, and most are found underwater. For example, a mid-ocean ridge, such as the Mid-Atlantic Ridge, has volcanoes caused by divergent tectonic plates whereas the Pacific Ring of Fire has volcanoes caused by convergent tectonic plates. Volcanoes can also form where there is stretching and thinning of the crust's plates, such as in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande rift in North America. Volcanism away from plate boundaries has been postulated to arise from upwelling diapirs from the core–mantle boundary, deep in the Earth. This results in hotspot volcanism, of which the Hawaiian hotspot is an example. Volcanoes are usually not created where two tectonic plates slide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In The United States
A list of volcanoes in the United States and its territories. Alaska American Samoa Arizona California Colorado Hawaii /[./[Https://www.sci.news/geology/puhahonu-shield-volcano-08435.html Puhahonu - - - Unknown Idaho Illinois Louisiana Michigan Mississippi Missouri Nevada New Hampshire New Jersey New Mexico Sierra Grande -. -. -. 2.41 to 2.88 million years ago Northern Mariana Islands Oregon Texas Utah Virginia Washington Wyoming See also *Geothermal energy in the United States *List of Cascade volcanoes * List of large volume volcanic eruptions in the Basin and Range Province * List of volcanoes in Canada *List of volcanoes in Mexico *List of volcanoes in Russia *List of volcanic craters in Alaska *List of volcanic craters in Ari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanic Craters In Alaska
The United States National Geodetic Survey lists thirteen craters in the state of Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., .... Aleutians East Borough, Alaska, Aleutians East Borough *Fisher Caldera is located on Unimak Island and named for American geologist Bernard Fisher (geologist), Bernard Fisher, who died on June 22, 1946, while exploring the Umnak Pass. It is by in area. Aleutians West Census Area, Alaska, Aleutians West Census Area *Mount Okmok, Okmok Caldera Bethel Census Area, Alaska, Bethel Census Area *Binalik Crater is located on Nunivak Island. It was named by the Yupik peoples, Yupik people, and reported in 1937. It is across. *Ikathiwik Crater *Nanwaksjiak Crater Kodiak Island *Kaguyak Crater Lake and Peninsula Borough, Alaska, Lake and Peni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Map Of Alaska Peninsula Volcanoes
A map is a symbolic depiction emphasizing relationships between elements of some space, such as objects, regions, or themes. Many maps are static, fixed to paper or some other durable medium, while others are dynamic or interactive. Although most commonly used to depict geography, maps may represent any space, real or fictional, without regard to context or scale, such as in brain mapping, DNA mapping, or computer network topology mapping. The space being mapped may be two dimensional, such as the surface of the earth, three dimensional, such as the interior of the earth, or even more abstract spaces of any dimension, such as arise in modeling phenomena having many independent variables. Although the earliest maps known are of the heavens, geographic maps of territory have a very long tradition and exist from ancient times. The word "map" comes from the , wherein ''mappa'' meant 'napkin' or 'cloth' and ''mundi'' 'the world'. Thus, "map" became a shortened term referring to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (geology)
The geologic time scale, or geological time scale, (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (scientific branch of geology that aims to determine the age of rocks). It is used primarily by Earth scientists (including geologists, paleontologists, geophysicists, geochemists, and paleoclimatologists) to describe the timing and relationships of events in geologic history. The time scale has been developed through the study of rock layers and the observation of their relationships and identifying features such as lithologies, paleomagnetic properties, and fossils. The definition of standardized international units of geologic time is the responsibility of the International Commission on Stratigraphy (ICS), a constituent body of the International Union of Geological Sciences (IUGS), whose primary objective is to precisely define gl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial.Oxford University Press – Why Geography Matters: More Than Ever (book) – "Holocene Humanity" section https://books.google.com/books?id=7P0_sWIcBNsC The Holocene corresponds with the rapid proliferation, growth and impacts of the human species worldwide, including all of its written history, technological revolutions, development of major civilizations, and overall significant transition towards urban living in the present. The human impact on modern-era Earth and its ecosystems may be considered of global si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Crater Lake
A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption. Formation Lakes in calderas fill large craters formed by the collapse of a volcano during an eruption. Lakes in maars fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the crater rim, is filled by water. The water may come from precipitation, groundwater circulation (often hydrothermal fluids in the case of volcanic craters) or melted ice. Its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the upper portion of the lake is contained only by its adjacent natural volcanic dam; continued leakage through or surface outflow ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
