A double summit, double peak, twin summit or twin peak refers to a mountain or hill that has two summits, separated by a col or saddle. One well known double summit is Austria’s highest mountain, the Großglockner, where the main summit of the Großglockner is separated from that of the Kleinglockner by the Glocknerscharte col in the area of a geological fault. Other double summits have resulted from geological folding. For example, on Mont Withrow in British Columbia resistant sandstones form the limbs of the double summit, whilst the softer rock in the core of the fold was eroded. Triple peaks occur more - one example is the Rosengartenspitze in the Dolomites; the Illimani in Bolivia is an example of a quadruple summit. Well known double summits are: Schneeberg Kaiserstein in the massif of the Wetterin, Styria Lugauer in the Gesäuse, Styria Krippenstein Bischofsmütze in the Dachstein region Brietkogel and the Eiskogel in the Tennen Mountains, Salzburg state Karlspitzen in the Kaiser Mountains Roßstein and Buchstein, Upper Bavaria Klammspitze in the Ammergau Alps Guffert in the Rofan, Tyrol Grauspitz, Liechtenstein Furchetta in the Geisler Group Altmann in the Alpstein, East Switzerland Großglockner Seekarspitze Gleichenberge Lasörling in the Großvenediger, High Tauern Unterberghorn in eastern North Tyrol Wilde Kreuzspitze in the Zillertal Alps Rofelewand in the Ötztal Alps Watzespitze in the Kaunergrat, Ötztal Alps Wildspitze in the Weißkamm, Ötztal Alps Schwarzhorn and Weißhorn in South Tyrol Ortstock, Glarus Alps Aiguille du Dru in the Mont Blanc massif Aiguille Verte in the Mont Blanc region Smolikas in Greece Bubenik in Upper Lusatia Strohmberg in Upper Lusatia Špičák in the Ore Mountains Burgstadtl in the Duppau Mountains Schanzberge near Tischberg, South Bohemia Schwarze Mauer and Kamenec on the Upper Austrian-Bohemian border Großer Auerberg in the Harz Ehrenbürg, a Zeugenberg in Franconian Switzerland Hohenstoffeln Berguedà in the Pyrenees Pen y Fan in the Brecon Beacons Hasan Dağı in the region of Cappadocia, Turkey Ushba in Georgia Elbrus in the Caucasus Raja Gyepang in Central Lahaul, India Machapucharé in the Annapurna massif in the Himalayas, Nepal Chogolisa in the Karakorum, Pakistan Broad Peak with pre- and main summit in the Karakorum, China/Pakistan Gasherbrum IV, southern neighbour of Broad Peak in the Karakorum, Pakistan Mont Ross on the Kerguelen Islands Pico Duarte on Haiti Chaupi Orco in the Andes Ancohuma in the Andes The Brothers in the Olympic Mountains Double Peak in the Cascade Mountains Kaufmann Peaks in Banff National Park Canada
Copper River (Alaska)
The Copper River or Ahtna River, Ahtna Athabascan ‘Atna’tuu, "river of the Ahtnas", Tlingit Eeḵhéeni, "river of copper", is a 290-mile river in south-central Alaska in the United States. It drains a large region of the Wrangell Mountains and Chugach Mountains into the Gulf of Alaska, it is known for its extensive delta ecosystem, as well as for its prolific runs of wild salmon, which are among the most prized stocks in the world. The river is the tenth largest in the United States, as ranked by average discharge volume at its mouth; the Copper River rises out of the Copper Glacier, which lies on the northeast side of Mount Wrangell, in the Wrangell Mountains, within Wrangell-Saint Elias National Park. It begins by flowing due north in a valley that lies on the east side of Mount Sanford, turns west, forming the northwest edge of the Wrangell Mountains and separating them from the Mentasta Mountains to the northeast, it continues to turn southeast, through a wide marshy plain to Chitina, where it is joined from the southeast by the Chitina River.
The Copper River is 290 miles long. It drops an average of about 12 feet per mile, drains more than 24,000 square miles —an area the size of West Virginia; the river runs at an average of 7 miles per hour. Downstream from its confluence with the Chitina it flows southwest, passing through a narrow glacier-lined gap in the Chugach Mountains within the Chugach National Forest east of Cordova Peak. There is an extensive area of linear sand dunes up to 250 feet in height radiating from the mouth of the Copper River. Both Miles Glacier and Childs Glacier calve directly into the river; the Copper enters the Gulf of Alaska southeast of Cordova where it creates a delta nearly 50 miles wide. The name of the river comes from the abundant copper deposits along the upper river that were used by Alaska Native population and later by settlers from the Russian Empire and the United States. Extraction of the copper resources was problematic due to navigation difficulties at the river's mouth; the construction of the Copper River and Northwestern Railway from Cordova through the upper river valley from 1908 to 1911 allowed widespread extraction of the mineral resources, in particular from the Kennecott Mine, discovered in 1898.
The mine was abandoned in 1938 and is now a ghost town tourist attraction and historic district maintained by the National Park Service. Copper River Highway runs from Cordova to the lower Copper River near Childs Glacier, following the old railroad route and ending at the reconstructed Million Dollar Bridge across the river; the Tok Cut-Off follows the Copper River Valley on the north side of the Chugach Mountains. The river's famous salmon runs arise from the use of the river watershed by over 2 million salmon each year for spawning; the extensive runs result in many unique varieties, prized for their fat content. The river's commercial salmon season is brief, beginning in May for chinook salmon and sockeye salmon for periods lasting days or hours at a time. Sport fishing by contrast is open all year long, but peak season on the Copper River lasts from August to September when the coho salmon runs; the fisheries are co-managed by the Alaska Department of Fish and Game and the Department of the Interior Federal Subsistence Board.
Management data are obtained by ADF&G at the Miles Lake sonar station and the native village of Eyak at the Baird Canyon and Canyon Creek research stations. The Copper River Delta, which extends for 700,000 acres, is the largest contiguous wetlands along the Pacific coast of North America, it is used annually by 16 million shorebirds, including the world's entire population of western sandpipers and dunlins. It is home to the world's largest population of nesting trumpeter swans and is the only known nesting site for the dusky Canada goose subspecies. List of rivers of Alaska Brabets, Timothy P.. Geomorphology of the Lower Copper River, Alaska. Washington, D. C.: U. S. Department of the Interior, U. S. Geological Survey. Ecotrust Copper River Program Copper River salmon habitat management study Prepared for Ecotrust by Marie E. Lowe of the Institute of Social and Economic Research, hosted by Alaska State Publications Program Alaska Department of Fish and Game: Copper River Salmon Eyak Preservation Council Nature Conservancy: Copper River Delta The Copper River Watershed Project NVE Fisheries Research and Seasonal Employment on the Copper River Cordova District Fishermen United Wrangell-St.
Elias National Park information Copper River | Chitina Dipnet Fishery Escapement Charts
Denali is the highest mountain peak in North America, with a summit elevation of 20,310 feet above sea level. With a topographic prominence of 20,156 feet and a topographic isolation of 4,629 miles, Denali is the third most prominent and third most isolated peak on Earth, after Mount Everest and Aconcagua. Located in the Alaska Range in the interior of the U. S. state of Alaska, Denali is the centerpiece of Preserve. The Koyukon people who inhabit the area around the mountain have referred to the peak as "Denali" for centuries. In 1896, a gold prospector named it "Mount McKinley" in support of then-presidential candidate William McKinley. In August 2015, following the 1975 lead of the State of Alaska, the United States Department of the Interior announced the change of the official name of the mountain to Denali. In 1903, James Wickersham recorded the first attempt at climbing Denali, unsuccessful. In 1906, Frederick Cook claimed the first ascent, proven to be false; the first verifiable ascent to Denali's summit was achieved on June 7, 1913, by climbers Hudson Stuck, Harry Karstens, Walter Harper, Robert Tatum, who went by the South Summit.
In 1951, Bradford Washburn pioneered the West Buttress route, considered to be the safest and easiest route, therefore the most popular in use. On September 2, 2015, the U. S. Geological Survey announced that the mountain is 20,310 feet high, not 20,320 feet, as measured in 1952 using photogrammetry. Denali is a granitic pluton lifted by tectonic pressure from the subduction of the Pacific Plate beneath the North American Plate; the forces that lifted Denali cause many deep earthquakes in Alaska and the Aleutian Islands. The Pacific Plate is seismically active beneath Denali, a tectonic region, known as the "McKinley cluster". Denali has a summit elevation of 20,310 feet above sea level, making it the highest peak in North America and the northernmost mountain above 6,000 meters elevation in the world. Measured from base to peak at some 18,000 ft, it is among the largest mountains situated above sea level. Denali rises from a sloping plain with elevations from 1,000 to 3,000 ft, for a base-to-peak height of 17,000 to 19,000 ft.
By comparison, Mount Everest rises from the Tibetan Plateau at a much higher base elevation. Base elevations for Everest range from 13,800 ft on the south side to 17,100 ft on the Tibetan Plateau, for a base-to-peak height in the range of 12,000 to 15,300 ft. Denali's base-to-peak height is little more than half the 33,500 ft of the volcano Mauna Kea, which lies under water. Denali has two significant summits: the South Summit is the higher one, while the North Summit has an elevation of 19,470 ft and a prominence of 1,270 ft; the North Summit is sometimes counted as sometimes not. Five large glaciers flow off the slopes of the mountain; the Peters Glacier lies on the northwest side of the massif, while the Muldrow Glacier falls from its northeast slopes. Just to the east of the Muldrow, abutting the eastern side of the massif, is the Traleika Glacier; the Ruth Glacier lies to the southeast of the mountain, the Kahiltna Glacier leads up to the southwest side of the mountain. With a length of 44 mi, the Kahiltna Glacier is the longest glacier in the Alaska Range.
The Koyukon Athabaskans who inhabit the area around the mountain have for centuries referred to the peak as Dinale or Denali. The name is based on a Koyukon word for "high" or "tall". During the Russian ownership of Alaska, the common name for the mountain was Bolshaya Gora, the Russian translation of Denali, it was called Densmore's Mountain in the late 1880s and early 1890s after Frank Densmore, an Alaskan prospector, the first European to reach the base of the mountain. In 1896, a gold prospector named it McKinley as political support for then-presidential candidate William McKinley, who became president the following year; the United States formally recognized the name Mount McKinley after President Wilson signed the Mount McKinley National Park Act of February 26, 1917. In 1965, Lyndon B. Johnson declared the north and south peaks of the mountain the "Churchill Peaks", in honor of British statesman Winston Churchill; the Alaska Board of Geographic Names changed the name of the mountain to Denali in 1975, how it is called locally.
However, a request in 1975 from the Alaska state legislature to the United States Board on Geographic Names to do the same at the federal level was blocked by Ohio congressman Ralph Regula, whose district included McKinley's hometown of Canton. On August 30, 2015, just ahead of a presidential visit to Alaska, the Barack Obama administration announced the name Denali would be restored in line with the Alaska Geographic Board's designation. U. S. Secretary of the Interior Sally Jewell issued the order changing the name to Denali on August 28, 2015, effective immediately. Jewell said the change had been "a long time coming"; the renaming of the mountain received praise from Alaska's senior U. S. senator, Lisa Murkowski, who had introduced legislation to accomplish the name change, but it drew criticism from several politicians from Pres
Mount Blackburn is the highest peak in the Wrangell Mountains of Alaska in the United States. It is the twelfth-highest peak in North America; the mountain is an old, eroded shield volcano, the second-highest volcano in the U. S. behind Mount Bona and the fifth-highest in North America. It was named in 1885 by Lt. Henry T. Allen of the U. S. Army after Joseph Clay Stiles Blackburn, a U. S. senator from Kentucky. It is located in the heart of Wrangell – St. Elias National Park, the largest national park in the country; the mountain's massif is covered entirely by icefields and glaciers, is the principal source of ice for the Kennicott Glacier, which flows southeast over 20 miles to just above the town of McCarthy. The mountain contributes a large volume of ice to the north-flowing Nabesna Glacier and the Kuskulana Glacier system. Mount Blackburn is a large, dramatic peak, with great local relief and independence from higher peaks, its west face drops over 11,000 ft to the Kuskulana Glacier in less than 4 horizontal miles.
Its other faces drop 8,000–10,000 ft, all in less than 8 miles. The toe of the Kuskulana Glacier, less than 12 miles from the summit, lies at an elevation of 2,400 ft, giving a rise of 14,000 ft. While these figures speak to the peak's relief, one measure of its independence is that it is the 50th-most topographically prominent peak in the world; the western of Blackburn's two summits is the mountain's highest point, a fact, not understood until the 1960s when new USGS maps were published. The first ascent of the west peak, hence Mount Blackburn, was done on May 30, 1958, by Bruce Gilbert, Dick Wahlstrom, Hans Gmoser, Adolf Bitterlich, Leon Blumer via the North Ridge; this team made the first ascent of Blackburn, but did not know it at the time due to the incorrect identification of the highest point. In fact, Blumer's article in the 1959 American Alpine Journal is titled "Mount Blackburn – Second Ascent." Kennedy Peak, or East Blackburn, 16,286 ft, is the eastern summit and was thought to be the highest point.
The first ascent of this summit was made in 1912 by Dora Keen and George Handy via the Kennicott Glacier and East Face. This heady exploit was ahead of its time. Dora Keen, driven by a deep desire for the climb, solicited miners from the nearby Kennecott Copper Mines, forged a route up the crevassed East Face to the East Peak, but did not traverse over to the West Peak. Keen went on to write a famous article for the Saturday Evening Post titled, "First up Mount Blackburn." In 1912, Keen and Handy thought. Mount Blackburn represents the eroded core of a shield volcano; because it is shrouded in permanent ice, its internal structure cannot be determined. It is believed to have a summit caldera modified by glaciation; the oldest rocks in the area are granites, about 4.2 million years old, representing an intrusive mass. The majority of the mountain is 3.4 million year old granite. From this it is inferred that a caldera collapse took place between 4.2 and 3.4 million years ago, after which activity ceased.
Today's standard route on the peak is the 1958 ascent route, the North Ridge, approached from the Nabesna Glacier, on the north side of the mountain, opposite from Keen and Hardy's route. The route starts from an airstrip on the glacier at an altitude of 7,200 feet, it is a moderate climb by Alaskan standards. List of mountain peaks of North America List of mountain peaks of the United States List of mountain peaks of Alaska List of the highest major summits of the United States List of the most prominent summits of the United States List of the most isolated major summits of the United States List of volcanoes in the United States Wood, Michael. Alaska: A Climbing Guide. Mountaineers Books. ISBN 0-89886-724-X. Richter, Donald H.. Guide to the Volcanoes of the Western Wrangell Mountains, Alaska. USGS Bulletin 2072. Winkler, Gary R.. A Geologic Guide to Wrangell—Saint Elias National Park and Preserve, Alaska: A Tectonic Collage of Northbound Terranes. USGS Professional Paper 1616. ISBN 0-607-92676-7.
Richter, Donald H.. Geologic Map of the Wrangell-Saint Elias National Park and Preserve, Alaska. USGS Scientific Investigations Map 2877
A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, gases to escape from a magma chamber below the surface. Earth's volcanoes occur because its crust is broken into 17 major, rigid tectonic plates that float on a hotter, softer layer in its mantle. Therefore, on Earth, volcanoes are found where tectonic plates are diverging or converging, most are found underwater. For example, a mid-oceanic 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 form where there is stretching and thinning of the crust's plates, e.g. in the East African Rift and the Wells Gray-Clearwater volcanic field and Rio Grande Rift in North America. This type of volcanism falls under the umbrella of "plate hypothesis" volcanism. Volcanism away from plate boundaries has been explained as mantle plumes; these so-called "hotspots", for example Hawaii, are postulated to arise from upwelling diapirs with magma from the core–mantle boundary, 3,000 km deep in the Earth.
Volcanoes are not created where two tectonic plates slide past one another. Erupting volcanoes can pose many hazards, not only in the immediate vicinity of the eruption. One such hazard is that volcanic ash can be a threat to aircraft, in particular those with jet engines where ash particles can be melted by the high operating temperature. Large eruptions can affect temperature as ash and droplets of sulfuric acid obscure the sun and cool the Earth's lower atmosphere. Volcanic winters have caused catastrophic famines; the word volcano is derived from the name of Vulcano, a volcanic island in the Aeolian Islands of Italy whose name in turn comes from Vulcan, the god of fire in Roman mythology. The study of volcanoes is sometimes spelled vulcanology. At the mid-oceanic ridges, two tectonic plates diverge from one another as new oceanic crust is formed by the cooling and solidifying of hot molten rock; because the crust is thin at these ridges due to the pull of the tectonic plates, the release of pressure leads to adiabatic expansion and the partial melting of the mantle, causing volcanism and creating new oceanic crust.
Most divergent plate boundaries are at the bottom of the oceans. Black smokers are evidence of this kind of volcanic activity. Where the mid-oceanic ridge is above sea-level, volcanic islands are formed. Subduction zones are places where two plates an oceanic plate and a continental plate, collide. In this case, the oceanic plate subducts, or submerges, under the continental plate, forming a deep ocean trench just offshore. In a process called flux melting, water released from the subducting plate lowers the melting temperature of the overlying mantle wedge, thus creating magma; this magma tends to be viscous because of its high silica content, so it does not attain the surface but cools and solidifies at depth. When it does reach the surface, however, a volcano is formed. Typical examples are the volcanoes in the Pacific Ring of Fire. Hotspots are volcanic areas believed to be formed by mantle plumes, which are hypothesized to be columns of hot material rising from the core-mantle boundary in a fixed space that causes large-volume melting.
Because tectonic plates move across them, each volcano becomes dormant and is re-formed as the plate advances over the postulated plume. The Hawaiian Islands are said to have been formed in such a manner; this theory, has been doubted. The most common perception of a volcano is of a conical mountain, spewing lava and poisonous gases from a crater at its summit; the features of volcanoes are much more complicated and their structure and behavior depends on a number of factors. Some volcanoes have rugged peaks formed by lava domes rather than a summit crater while others have landscape features such as massive plateaus. Vents that issue volcanic material and gases can develop anywhere on the landform and may give rise to smaller cones such as Puʻu ʻŌʻō on a flank of Hawaii's Kīlauea. Other types of volcano include cryovolcanoes on some moons of Jupiter and Neptune. Active mud volcanoes tend to involve temperatures much lower than those of igneous volcanoes except when the mud volcano is a vent of an igneous volcano.
Volcanic fissure vents are linear fractures through which lava emerges. Shield volcanoes, so named for their broad, shield-like profiles, are formed by the eruption of low-viscosity lava that can flow a great distance from a vent, they do not explode catastrophically. Since low-viscosity magma is low in silica, shield volcanoes are more common in oceanic than continental settings; the Hawaiian volcanic chain is a series of shield cones, they are common in Iceland, as well. Lava domes are built by slow eruptions of viscous lava, they are sometimes formed within the crater of a previous volcanic eruption, as in the case of Mount Saint Helen
A summit is a point on a surface, higher in elevation than all points adjacent to it. The topographic terms acme, apex and zenith are synonymous; the term top is used only for a mountain peak, located at some distance from the nearest point of higher elevation. For example, a big massive rock next to the main summit of a mountain is not considered a summit. Summits near a higher peak, with some prominence or isolation, but not reaching a certain cutoff value for the quantities, are considered subsummits of the higher peak, are considered part of the same mountain. A pyramidal peak is an exaggerated form produced by ice erosion of a mountain top. Summit may refer to the highest point along a line, trail, or route; the highest summit in the world is Everest with height of 8844.43 m above sea level. The first official ascent was made by Sir Edmund Hillary, they reached the mountain`s peak in 1953. Whether a highest point is classified as a summit, a sub peak or a separate mountain is subjective; the UIAA definition of a peak is.
Otherwise, it's a subpeak. In many parts of the western United States, the term summit refers to the highest point along a road, highway, or railroad. For example, the highest point along Interstate 80 in California is referred to as Donner Summit and the highest point on Interstate 5 is Siskiyou Mountain Summit. A summit climbing differs from the common mountaineering. Summit expedition requires: 1+ year of training, a good physical shape, a special gear. Although a huge part of climber’s stuff can be left and taken at the base camps or given to porters, there is a long list of personal equipment. In addition to common mountaineers’ gear, Summit climbers need to take Diamox and bottles of oxygen. There are special requirements for crampons, ice axe, rappel device, etc. Geoid Hill – Landform that extends above the surrounding terrain Nadir Summit accordance Peak finder Summit Climbing Gear List
The Wrangell Mountains are a high mountain range of eastern Alaska in the United States. Much of the range is included in Preserve; the Wrangell Mountains are entirely volcanic in origin, 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, one of the largest andesite shield volcanoes in the world, the only presently active volcano in the range; the Wrangell Mountains comprise most of the Wrangell Volcanic Field, which 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 north of the Wrangell Mountains are therefore among the coldest areas of North America during the winter.
The Wrangell Mountains include 12 of the 40+ Alaskan peaks over 13,000 feet: Mount Blackburn, 16,390 feet, East Summit, 16,286 ft Mount Sanford, 16,237 feet, South Peak, 13,654 ft Mount Wrangell, 14,163 feet, West Summit, 14,013 ft Atna Peaks, 13,860 ft Regal Mountain, 13,845 ft Mount Jarvis, 13,421 feet, North Peak, 13,025 ft Parka Peak, 13,280 ft Mount Zanetti, 13,009 ft Other prominent mountains include: Mount Drum, 12,010 ft The mountains are named after explorer, president of Russian-American Company, admiral Ferdinand von Wrangel. American folk singer John Denver wrote a song, "The Wrangell Mountain Song", in reference to the range. Wrangellia Terrane Wrangell-St. Elias National Park & Preserve Wrangell Mountains Center