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Arctic Alaska
Arctic Alaska or Far North Alaska is a region of the United States, U.S. U.S. state, state of Alaska generally referring to the northern areas on or close to the Arctic Ocean. It commonly includes North Slope Borough, Alaska, North Slope Borough, Northwest Arctic Borough, Alaska, Northwest Arctic Borough, Nome Census Area, Alaska, Nome Census Area, and is sometimes taken to include parts of the Yukon-Koyukuk Census Area, Alaska, Yukon-Koyukuk Census Area. Some notable towns there include Prudhoe Bay, Alaska, Prudhoe Bay, Utqiaġvik, Kotzebue, Alaska, Kotzebue, Nome, Alaska, Nome and Galena, Alaska, Galena, although some of these are not in the Arctic Circle proper. Most of these communities have no highways and can only be reached by aircraft or snowmobile in good weather. Originally inhabited by various Alaska Native groups living off hunting, whaling, or salmon fishing, modern settlement in Arctic Alaska was driven first by discoveries of gold and later on by the extractio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arctic Circle
The Arctic Circle is one of the two polar circles, and the northernmost of the five major circle of latitude, circles of latitude as shown on maps of Earth at about 66° 34' N. Its southern counterpart is the Antarctic Circle. The Arctic Circle marks the southernmost latitude at which, on the winter solstice in the Northern Hemisphere, the Sun does not rise all day, and on the Northern Hemisphere's summer solstice, the Sun does not set. These phenomena are referred to as polar night and midnight sun respectively, and the further north one progresses, the more obvious this becomes. For example, in the Russian port city of Murmansk, three degrees north of the Arctic Circle, the Sun stays below the horizon for 20 days before and after the winter solstice, and above the horizon for 20 days before and after the summer solstice. The position of the Arctic Circle is not fixed and currently runs north of the Equator. Its latitude depends on Earth's axial tilt, which axial precession, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Highway
A highway is any public or private road or other public way on land. It includes not just major roads, but also other public roads and rights of way. In the United States, it is also used as an equivalent term to controlled-access highway, or a translation for ''motorway'', ''Autobahn'', ''autostrada'', ''autoroutes of France, autoroute'', etc. According to Merriam-Webster, the use of the term predates the 12th century. According to Online Etymology Dictionary, Etymonline, "high" is in the sense of "main". In North American English, North American and Australian English, major roads such as controlled-access highways or arterial (road), arterial roads are often state highways (Canada: provincial highways). Other roads may be designated "county highways" in the US and Ontario. These classifications refer to the level of government (state, provincial, county) that maintains the roadway. In British English, "highway" is primarily a legal term. Everyday use normally implies roads, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bear
Bears are carnivoran mammals of the family (biology), family Ursidae (). They are classified as caniforms, or doglike carnivorans. Although only eight species of bears are extant, they are widespread, appearing in a wide variety of habitats throughout most of the Northern Hemisphere and partially in the Southern Hemisphere. Bears are found on the continents of North America, South America, and Eurasia. Common characteristics of modern bears include large bodies with stocky legs, long snouts, small rounded ears, shaggy hair, plantigrade paws with five nonretractile claws, and short tails. While the polar bear is mostly carnivorous, and the giant panda is mostly herbivorous, the remaining six species are omnivorous with varying diets. With the exception of courtship display, courting individuals and mothers with their young, bears are typically solitary animals. They may be diurnality, diurnal or nocturnal and have an excellent sense of smell. Despite their heavy build and awk ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coastal Plain
A coastal plain (also coastal plains, coastal lowland, coastal lowlands) is an area of flat, low-lying land adjacent to a sea coast. A fall line commonly marks the border between a coastal plain and an upland area. Formation Coastal plains can form in one of two ways; some begin as a continental shelf, a flat piece of land located below sea level, and are created when the ocean level falls, exposing the land. Others develop when river currents carry sediment into the ocean, which is deposited and builds up over time until it forms a coastal plain. They are generally separated from the rest of the interior by proximate landforms, like mountains. Locations Some of the largest coastal plains are in Alaska and the southeastern United States. The Gulf Coastal Plain of North America extends northwards from the Gulf of Mexico along the Lower Mississippi River to the Ohio River, which is a distance of about . The Atlantic Coastal Plain runs from the New York Bight to Florida. The C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Range
A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arisen from the same cause, usually an orogeny. Mountain ranges are formed by a variety of geological processes, but most of the significant ones on Earth are the result of plate tectonics. Mountain ranges are also found on many planetary mass objects in the Solar System and are likely a feature of most terrestrial planets. Mountain ranges are usually segmented by highlands or mountain passes and valleys. Individual mountains within the same mountain range do not necessarily have the same geologic structure or petrology. They may be a mix of different orogenic expressions and terranes, for example thrust sheets, uplifted blocks, fold mountains, and volcanic landforms resulting in a variety of rock types. Major ranges Most geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic, Antarctic. Tundra vegetation is composed of dwarf shrubs, Cyperaceae, sedges, Poaceae, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained greenhouse gases into the atmosphere, creating Climate change feedback, a feedback cycle t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal Environmental factor, factors. External factors—including climate—control the ecosystem's structure, but are not influenced by it. By contrast, internal factors control and are controlled by ecosystem processes; these include decomposition, the types of species present, root competition, shading, disturbance, and succession. While external factors generally determine which Resource (biology), resource inputs an ecosystem has, their availability within the ecosystem is controlled by internal factors. Ecosystems are wikt:dynamic, dynamic, subject to periodic disturbances and always in the process of recovering from past disturbances. The tendency of an ecosystem to remain clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extraction Of Petroleum
Petroleum is a fossil fuel that can be drawn from beneath the Earth's surface. Reservoirs of petroleum are formed through the mixture of plants, algae, and sediments in shallow seas under high pressure. Petroleum is mostly recovered from oil drilling. Seismic surveys and other methods are used to locate oil reservoirs. Oil rigs and oil platforms are used to drill long holes into the earth to create an oil well and extract petroleum. After extraction, oil is refined to make gasoline and other products such as tires and refrigerators. Extraction of petroleum can be dangerous and has led to oil spills. Locating the oil field Geologists and geophysicists use seismic surveys to search for geological structures that may form oil reservoirs. The "classic" method includes making an underground explosion nearby and observing the seismic response, which provides information about the geological structures underground. However, "passive" methods that extract information from naturall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gold
Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal, a group 11 element, and one of the noble metals. It is one of the least reactivity (chemistry), reactive chemical elements, being the second-lowest in the reactivity series. It is solid under standard temperature and pressure, standard conditions. Gold often occurs in free elemental (native state (metallurgy), native state), as gold nugget, nuggets or grains, in rock (geology), rocks, vein (geology), veins, and alluvial deposits. It occurs in a solid solution series with the native element silver (as in electrum), naturally alloyed with other metals like copper and palladium, and mineral inclusions such as within pyrite. Less commonly, it occurs in minerals as gold compounds, often with tellurium (gold tellurides). Gold is resistant to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing
Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment (Freshwater ecosystem, freshwater or Marine ecosystem, marine), but may also be caught from Fish stocking, stocked Body of water, bodies of water such as Fish pond, ponds, canals, park wetlands and reservoirs. Fishing techniques include trawling, Longline fishing, longlining, jigging, Fishing techniques#Hand-gathering, hand-gathering, Spearfishing, spearing, Fishing net, netting, angling, Bowfishing, shooting and Fish trap, trapping, as well as Destructive fishing practices, more destructive and often Illegal, unreported and unregulated fishing, illegal techniques such as Electrofishing, electrocution, Blast fishing, blasting and Cyanide fishing, poisoning. The term fishing broadly includes catching aquatic animals other than fish, such as crustaceans (shrimp/lobsters/crabs), shellfish, cephalopods (octopus/squid) and echinoderms (starfish/sea urchins). The term is n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmon
Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native to tributary, tributaries of the North Atlantic (''Salmo'') and North Pacific (''Oncorhynchus'') basins. ''Salmon'' is a colloquial or common name used for fish in this group, but is not a scientific name. Other closely related fish in the same family include trout, Salvelinus, char, Thymallus, grayling, Freshwater whitefish, whitefish, lenok and Hucho, taimen, all coldwater fish of the subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia. Salmon are typically fish migration, anadromous: they hatch in the shallow gravel stream bed, beds of freshwater headstreams and spend their juvenile fish, juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska Native
Alaska Natives (also known as Native Alaskans, Alaskan Indians, or Indigenous Alaskans) are the Indigenous peoples of the Americas, Indigenous peoples of Alaska that encompass a diverse arena of cultural and linguistic groups, including the Iñupiat, Yupik peoples, Yupik, Aleut people, Aleut, Eyak people, Eyak, Tlingit people, Tlingit, Haida people, Haida, Tsimshian, and various Alaskan Athabaskans, Northern Athabaskan, as well as Russian Creoles. These groups are often categorized by their distinct language families. Many Alaska Natives are enrolled in federally recognized Alaska Native tribal entities, which are members of 13 Alaska Native Regional Corporations responsible for managing land and financial claims. The migration of Alaska Natives' ancestors into the Alaskan region occurred thousands of years ago, likely in more than one wave. Some present-day groups descend from a later migration event that also led to settlement across northern North America, with these popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
