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Anyuyskiy
Anyuyskiy (russian: Анюйский Вулкан; ''Annuyskiy Vulkan'') is an extinct volcano in the Anyuy Mountains, Chukotka Autonomous Okrug, Far Eastern Russia. It is formed by two systems: one is formed by long lava flows which disrupted the valley of the Monni River. Later, a volcanic cone formed, experiencing explosive activity and eventually extruding a long lava flow. The volcano erupted more than one cubic kilometre of lava. It was considered to have been active during the 14th and 18th centuries, but radiometric dating has shown ages of almost 250,000 years ago. The volcano is also known as Molodykh, Monni and Ustieva. Anyuyskiy was discovered in 1952 on aerial images. Geology Anyuyskiy is in the valley of the Monni River, in the southern Anyuy Mountains, part of the East Siberian System. Late Quaternary volcanic activity appears to be linked to tectonic activity in the area. A change in volcanic activity from linear vents to central vents has been noted. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anyuy Range
The Anyuy Mountains (russian: Анюйский хребет; ''Anyuyskiy Khrebet''), also known as South Anyuy Range are a range of mountains in far north-eastern Russia. Administratively the range is part of the Chukotka Autonomous Okrug, Russia. The area of the range is largely uninhabited. Geography To the north rises the Chuvanay Range and to the northeast the Ilirney Range, on the other side of the Maly Anyuy River. The Anyuy Range is part of the East Siberian System of mountains and is one of the subranges of the Anadyr Highlands. To the east of the eastern end of the range rises the Shchuchy Range, stretching in a roughly southwestern direction, and to the south of the range rises the roughly parallel Oloy Range of the Kolyma Mountains. Although there are no glaciers in the range in present times, there is evidence of ancient glaciation. The Anyuy Range is drained by rivers Maly Anyuy, Bolshoy Anyuy, and Omolon. The highest point is high Blokhin Peak (Пик Блохин ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anyuy Mountains
The Anyuy Mountains (russian: Анюйский хребет; ''Anyuyskiy Khrebet''), also known as South Anyuy Range are a range of mountains in far north-eastern Russia. Administratively the range is part of the Chukotka Autonomous Okrug, Russia. The area of the range is largely uninhabited. Geography To the north rises the Chuvanay Range and to the northeast the Ilirney Range, on the other side of the Maly Anyuy River. The Anyuy Range is part of the East Siberian System of mountains and is one of the subranges of the Anadyr Highlands. To the east of the eastern end of the range rises the Shchuchy Range, stretching in a roughly southwestern direction, and to the south of the range rises the roughly parallel Oloy Range of the Kolyma Mountains. Although there are no glaciers in the range in present times, there is evidence of ancient glaciation. The Anyuy Range is drained by rivers Maly Anyuy, Bolshoy Anyuy, and Omolon. The highest point is high Blokhin Peak (Пик Блохин ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluchin (volcano)
Aluchin is a volcano along the Aluchin River in the Chukotka Autonomous Okrug of Russia. The volcano was discovered in 1956–1957 by G.K. Kleshchev. Description The volcano is formed by three cones, named Alpha, Beta and Gamma, which occur along a fissure. Alpha, the main cone, formed within a river valley. It is high and has a diameter of . A crater wide and deep caps the cone. Beta, a smaller cone formed by lava and scoria, grew on the southeastern side of Alpha. It ejected lava bombs with sizes of up to that landed in the surrounding valleys. Beta is partially degraded, high and has a wide crater. Gamma is formed by agglomerates. Because the poorly indurated agglomerates are subject to rapid erosion the cone's structure has been heavily degraded. It is high with no recognizable crater and a base size of . Volcanic activity has generated lava flows that fill a valley. These flows cover a surface area of and reach a length of . The total volume reached by the flows is , o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chukotka Autonomous Okrug
Chukotka (russian: Чуко́тка), officially the Chukotka Autonomous Okrug,, ''Čukotkakèn avtonomnykèn okrug'', is the easternmost federal subjects of Russia, federal subject of Russia. It is an autonomous okrug situated in the Russian Far East, and shares a border with the Sakha, Sakha Republic to the west, Magadan Oblast to the south-west, and Kamchatka Krai to the south. Anadyr (town), Anadyr is the largest types of inhabited localities in Russia, town and the administrative center, capital, and the easternmost settlement to have town status in Russia. Chukotka is primarily populated by ethnic Russians, Chukchi people, Chukchi, and other Indigenous peoples of Siberia, indigenous peoples. It is the only autonomous okrug in Russia that is not included in, or subordinate to, another federal subject, having separated from Magadan Oblast in 1992. It is home to Lake Elgygytgyn, an impact crater lake, and Anyuyskiy, an extinct volcano. The village of Uelen is the easternmos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 remain as tephra unless hot enough to fuse into pyroclastic rock or tuff. Tephrochronology is a geochronological technique that uses discrete layers of tephra—volcanic ash from a single eruption—to create a chronological framework in which paleoenvironmental or archaeological records can be placed. When a volcano explodes, it releases a variety of tephra including ash, cinders, and blocks. These layers settle on the land and, over time, sedimentation occurs incorporating these tephra layers into the geologic record. Often, when a volcano explodes, biological organisms are killed and their remains are buried within the tephra layer. These fossils are later dated by scientists to determine the age of the fossil and its place within the geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permafrost
Permafrost is ground that continuously remains below 0 °C (32 °F) for two or more years, located on land or under the ocean. Most common in the Northern Hemisphere, around 15% of the Northern Hemisphere or 11% of the global surface is underlain by permafrost, with the total area of around 18 million km2. This includes substantial areas of Alaska, Greenland, Canada and Siberia. It can also be located on mountaintops in the Southern Hemisphere and beneath ice-free areas in the Antarctic. Permafrost does not have to be the first layer that is on the ground. It can be from an inch to several miles deep under the Earth's surface. It frequently occurs in ground ice, but it can also be present in non-porous bedrock. Permafrost is formed from ice holding various types of soil, sand, and rock in combination. Permafrost contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide, making tundra soil a carbon sink. As global war ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Granitoid
A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quartz-poor monzonites to quartz-rich quartzolites. As only two of the three defining mineral groups (quartz, plagioclase, and alkali feldspar) need to be present for the rock to be called a granitoid, foid-bearing rocks, which predominantly contain feldspars but no quartz, are also granitoids. The terms ''granite'' and ''granitic rock'' are often used interchangeably for granitoids; however, granite is just one particular type of granitoid. Granitoids are diverse; no classification system for granitoids can give a complete and unique characterization of the origin, compositional evolution, and geodynamic environment for the genesis of a granitoid. Accordingly, multiple granitoid classification systems have been developed such as those based o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Explosive Eruption
In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such that expelled lava violently froths into volcanic ash when pressure is suddenly lowered at the vent. Sometimes a lava plug will block the conduit to the summit, and when this occurs, eruptions are more violent. Explosive eruptions can expel as much as per second of rocks, dust, gas and pyroclastic material, averaged over the duration of eruption, that travels at several hundred meters per second as high as into the atmosphere. This cloud may subsequently collapse, creating a fast-moving pyroclastic flow of hot volcanic matter. Stages of an explosive eruption An explosive eruption begins with some form of blockage in the crater of a volcano that prevents the release of gases trapped in highly viscous andesitic or rhyolitic magma. The pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ʻaʻā
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trachybasalt
Trachybasalt is a volcanic rock with a composition between trachyte and basalt. It resembles basalt but has a high content of alkali metal oxides. Minerals in trachybasalt include alkali feldspar, calcic plagioclase, olivine, clinopyroxene and likely very small amounts of leucite or analcime. Description An aphanitic (fine-grained) igneous rock is classified as trachybasalt when it has a silica content of about 49% and a total alkali metal oxide content of about 6%. This places trachybasalt in the S1 field of the TAS classification, TAS diagram. Trachybasalt is further divided into sodium-rich ''hawaiite'' and potassium-rich ''potassic trachybasalt'', with wt% > + 2 for hawaiite. The intrusive equivalent of trachybasalt is monzonite. Trachybasalt is not defined on the QAPF diagram, which classifies crystalline igneous rock by its relative content of feldspars and quartz. However, the U.S. Geological Survey defines trachybasalt as a mafic volcanic rock (composed of over 35% maf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyroclastic Cone
Volcanic cones are among the simplest volcanic landforms. They are built by ejecta from a volcanic vent, piling up around the vent in the shape of a cone with a central crater. Volcanic cones are of different types, depending upon the nature and size of the fragments ejected during the eruption. Types of volcanic cones include stratocones, spatter cones, tuff cones, and cinder cones. Stratocone Stratocones are large cone-shaped volcanoes made up of lava flows, explosively erupted pyroclastic rocks, and igneous intrusives that are typically centered around a cylindrical vent. Unlike shield volcanoes, they are characterized by a steep profile and periodic, often alternating, explosive eruptions and effusive eruptions. Some have collapsed craters called calderas. The central core of a stratocone is commonly dominated by a central core of intrusive rocks that range from around to over several kilometers in diameter. This central core is surrounded by multiple generations of lava f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Lake
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified (sometimes referred to as ''frozen lava lakes''). Formation Lava lakes can form in three ways: *from one or more vents in a crater that erupts enough lava to partially fill the crater; or *when lava pours into a crater or broad depression and partially fills the crater; or *atop a new vent that erupts lava continuously for a period of several weeks or more and slowly builds a crater progressively higher than the surrounding ground. Behaviors Lava lakes occur in a variety of volcanic systems, ranging from the basaltic Erta Ale lake in Ethiopia and the basaltic andesite volcano of Villarrica, Chile, to the unique phonolitic lava lake at Mt. Erebus, Antarctica. Lava lakes have been observed to exhibit a range of behaviours. A "constantly circulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
