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Porphyry Mountain (Montana)
Porphyry Mountain is a prominent 6,375-foot (1,943 meter) mountain summit located in the Wrangell Mountains, in the U.S. state of Alaska. The peak is situated in Wrangell-St. Elias National Park and Preserve, immediately southeast of Kennecott, northeast of McCarthy, and, northwest of Sourdough Peak. Precipitation runoff from the mountain drains into tributaries of the Nizina River, which in turn is part of the Copper River drainage basin. The peak is notable for a rock glacier on its north slope. The mountain was so named because it is largely composed of porphyry, which is a very hard igneous rock. The mountain's local name was reported in 1908 by the U.S. Geological Survey. On a clear day the summit of Porphyry Mountain offers views of Donoho Peak, Kennicott Glacier, and Mount Blackburn to the northwest, and Fireweed Mountain to the west. Climate Based on the Köppen climate classification, Porphyry Mountain is located in a subarctic climate The subarctic climate ...
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Wrangell Mountains
The Wrangell Mountains are a high mountain range of eastern Alaska in the United States. Much of the range is included in Wrangell-Saint Elias National Park and Preserve. The Wrangell Mountains are almost entirely volcanic in origin, and they include the second and third highest volcanoes in the United States, Mount Blackburn and Mount Sanford. The range takes its name from Mount Wrangell, which is one of the largest andesite shield volcanoes in the world, and also the only presently active volcano in the range. The Wrangell Mountains comprise most of the Wrangell Volcanic Field, which also extends into the neighboring Saint Elias Mountains and the Yukon Territory in Canada. The Wrangell Mountains are just to the northwest of the Saint Elias Mountains and northeast of the Chugach Mountains, which are along the coast of the Gulf of Alaska. These ranges have the combined effect of blocking the inland areas from warmer moist air over the Pacific Ocean. The inland areas to the no ...
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Rock (geology)
In geology, rock (or stone) is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition, and the way in which it is formed. Rocks form the Earth's outer solid layer, the crust, and most of its interior, except for the liquid outer core and pockets of magma in the asthenosphere. The study of rocks involves multiple subdisciplines of geology, including petrology and mineralogy. It may be limited to rocks found on Earth, or it may include planetary geology that studies the rocks of other celestial objects. Rocks are usually grouped into three main groups: igneous rocks, sedimentary rocks and metamorphic rocks. Igneous rocks are formed when magma cools in the Earth's crust, or lava cools on the ground surface or the seabed. Sedimentary rocks are formed by diagenesis and lithification of sediments, which in turn are formed by the weathering, transport, and deposition of existing ro ...
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Landforms Of Copper River Census Area, Alaska
A landform is a natural or anthropogenic land feature on the solid surface of the Earth or other planetary body. Landforms together make up a given terrain, and their arrangement in the landscape is known as topography. Landforms include hills, mountains, canyons, and valleys, as well as shoreline features such as bays, peninsulas, and seas, including submerged features such as mid-ocean ridges, volcanoes, and the great ocean basins. Physical characteristics Landforms are categorized by characteristic physical attributes such as elevation, slope, orientation, stratification, rock exposure and soil type. Gross physical features or landforms include intuitive elements such as berms, mounds, hills, ridges, cliffs, valleys, rivers, peninsulas, volcanoes, and numerous other structural and size-scaled (e.g. ponds vs. lakes, hills vs. mountains) elements including various kinds of inland and oceanic waterbodies and sub-surface features. Mountains, hills, plateaux, and plains are the fou ...
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Mountains Of Alaska
A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher than a hill, typically rising at least 300 metres (1,000 feet) above the surrounding land. A few mountains are isolated summits, but most occur in mountain ranges. Mountains are formed through tectonic forces, erosion, or volcanism, which act on time scales of up to tens of millions of years. Once mountain building ceases, mountains are slowly leveled through the action of weathering, through slumping and other forms of mass wasting, as well as through erosion by rivers and glaciers. High elevations on mountains produce colder climates than at sea level at similar latitude. These colder climates strongly affect the ecosystems of mountains: different elevations have different plants and animals. Because of the less hospitable terrain and ...
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Porphyry Mountain And National Creek Rock Glacier From Donoho Basin
__NOTOC__ Porphyry (; el, Πορφύριος, links=no, ''Porphyrios'' "purple-clad") may refer to: * Porphyry (geology), an igneous rock with large crystals in a fine-grained matrix and important Roman building material * Porphyritic, the general igneous texture of a rock with two distinct crystal (phenocryst) sizes * Porphyry copper deposit, a primary (low grade) ore deposit of copper, consisting of porphyry rocks * Tyrian purple or ''Porphyra'', a purple-red natural dye * "Porphyria's Lover", originally published as "Porphyria", a poem by Robert Browning * Porphyrian tree, classic device for illustrating hierarchy and ontology * Porphyria, a disease * Porphyrins, a group of organic compounds Places * Mons Porphyrites, the only porphyry quarry worked in the ancient world for the emperor's building works and statuary *Porphyry Island in Lake Superior, Canada * Porphyry Mountain in Alaska, Unites States * Porphyry, a system of astrological house division * Porphyry, a ...
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Geography Of Alaska
Alaska occupies the northwestern portion of the North American continent and is bordered only by Canada on the east. It is one of two U.S. states not bordered by another state; Hawaii is the other. Alaska has more ocean coastline than all of the other U.S. states combined. About of Canadian territory separate Alaska from Washington state. Alaska is thus an exclave of the United States that is part of the continental U.S. and the U.S. West Coast, but is not part of the contiguous U.S. Alaska is also the only state, other than Hawaii, whose capital city is accessible only via ship or air, because no roads connect Juneau to the rest of the continent. The state is bordered by Yukon and British Columbia, Canada to the east, the Gulf of Alaska and the Pacific Ocean to the south, Russia ( Chukotka Autonomous Okrug), Bering Sea, the Bering Strait, and Chukchi Sea to the west, and the Beaufort Sea and the Arctic Ocean to the north. Because it extends into the Eastern Hemisphere ...
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List Of Mountain Peaks Of Alaska
This article comprises three sortable tables of major mountain peaksThis article defines a significant summit as a summit with at least of topographic prominence, and a major summit as a susexxleast of topographic prominence. All summits in this article have at least 500 meters of topographic prominence. An ultra-prominent summit is a summit with at least of topographic prominence. of the U.S. State of Alaska. The summit of a mountain or hill may be measured in three principal ways: #The topographic elevation of a summit measures the height of the summit above a geodetic sea level.If the elevation or prominence of a summit is calculated as a range of values, the arithmetic mean is shown. The first table below ranks the 100 highest major summits of Alaska by elevation. #The topographic prominence of a summit is a measure of how high the summit rises above its surroundings.The topographic prominence of a summit is the topographic elevation difference between the s ...
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Orographic Lift
Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation. Orographic lifting can have a number of effects, including precipitation, rain shadowing, leeward winds, and associated clouds. Precipitation Precipitation induced by orographic lift occurs in many places throughout the world. Examples include: * The Mogollon Rim in central Arizona * The western slope of the Sierra Nevada range in California * The mountains near Baja California North – specifically La Bocana to Laguna Hanson. * The windward slopes of Khasi and Jayantia Hills (see Mawsynram) in the state of Meghalaya in India. * The Western Highlands of Yemen, which receive by far the most rain in Arabia. * The Western Ghats that run along India's western coast. * The Grea ...
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Gulf Of Alaska
The Gulf of Alaska (Tlingit: ''Yéil T'ooch’'') is an arm of the Pacific Ocean defined by the curve of the southern coast of Alaska, stretching from the Alaska Peninsula and Kodiak Island in the west to the Alexander Archipelago in the east, where Glacier Bay and the Inside Passage are found. The Gulf shoreline is a combination of forest, mountain and a number of tidewater glaciers. Alaska's largest glaciers, the Malaspina Glacier and Bering Glacier, spill out onto the coastal line along the Gulf of Alaska. The coast is heavily indented with Cook Inlet and Prince William Sound, the two largest connected bodies of water. It includes Yakutat Bay and Cross Sound. Lituya Bay (a fjord north of Cross Sound, and south of Mount Fairweather) is the site of the largest recorded tsunami in history. It serves as a sheltered anchorage for fishing boats. Ecology The Gulf of Alaska is considered a Class I, productive ecosystem with more than 300 grams of carbon per square meter per year ...
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Subarctic Climate
The subarctic climate (also called subpolar climate, or boreal climate) is a climate with long, cold (often very cold) winters, and short, warm to cool summers. It is found on large landmasses, often away from the moderating effects of an ocean, generally at latitudes from 50° to 70°N, poleward of the humid continental climates. Subarctic or boreal climates are the source regions for the cold air that affects temperate latitudes to the south in winter. These climates represent Köppen climate classification ''Dfc'', ''Dwc'', ''Dsc'', ''Dfd'', ''Dwd'' and ''Dsd''. Description This type of climate offers some of the most extreme seasonal temperature variations found on the planet: in winter, temperatures can drop to below and in summer, the temperature may exceed . However, the summers are short; no more than three months of the year (but at least one month) must have a 24-hour average temperature of at least to fall into this category of climate, and the coldest month should ave ...
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Köppen Climate Classification
The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notably in 1918 and 1936. Later, the climatologist Rudolf Geiger (1894–1981) introduced some changes to the classification system, which is thus sometimes called the Köppen–Geiger climate classification system. The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (temperate), ''D'' (continental), and ''E'' (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the ''E'' group are assigned a seasonal precipitation subgroup (the second letter). For example, ''Af'' indi ...
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Fireweed Mountain
Fireweed Mountain is a prominent 6,956-foot (2,120 meter) mountain summit located in the Wrangell Mountains, in the U.S. state of Alaska. The peak is situated in Wrangell-St. Elias National Park and Preserve, immediately west of the terminus of the Kennicott Glacier, and west-northwest of McCarthy, Alaska, McCarthy. Precipitation runoff from the eight-mile-long by five-mile-wide mountain drains into tributaries of the Chitina River, which in turn is part of the Copper River (Alaska), Copper River drainage basin. The mountain's name was given in the 1920s by Molly Gilmore, a lifelong resident of the McCarthy area, who at age 17, named the mountain for the abundance of fireweed which grew on the mountain following forest fires. Although fireweed is the most common and well-known flower in Alaska, it is not commemorated on any other Alaskan mountain. The mountain's name was officially adopted in 1966 by the U.S. Board on Geographic Names. On a clear day the summit of Fireweed Mountai ...
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