A pyramidal peak, sometimes called a glacial horn in extreme cases, is an angular, sharply pointed mountain peak which results from the cirque erosion due to multiple glaciers diverging from a central point. Pyramidal peaks are often examples of nunataks.
Glaciers, typically forming in drainages on the sides of a mountain, develop bowl-shaped basins called cirques (sometimes called 'corries' – from Scottish Gaelic coire [kʰəɾə] (a bowl) – or cwms). Cirque glaciers have rotational sliding that abrades the floor of the basin more than walls and that causes the bowl shape to form. As cirques are formed by glaciation in an alpine environment, the headwall and ridges between parallel glaciers called arêtes become more steep and defined. This occurs due to freeze/thaw and mass wasting beneath the ice surface. It is widely held[ by whom? ] that a common cause for headwall steepening and extension headward is the crevasses known as bergschrund that occur between the moving ice and the headwall. Plucking and shattering can be seen here by those exploring the crevasses. A cirque is exposed when the glacier that created it recedes.[ citation needed ]
When three or more of these cirques converge on a central point, they create a pyramid-shaped peak with steep walls. These horns are a common shape for mountain tops in highly glaciated areas. The number of faces of a horn depends on the number of cirques involved in the formation of the peak: three to four is most common. Horns with more than four faces include the Weissmies and the Mönch. [1] A peak with four symmetrical faces is called a Matterhorn (after the Matterhorn, a mountain in the Alps). [2]
The peak of a glacial horn will often outlast the arêtes on its flanks. [1] As the rock around it erodes, the horn gains in prominence. Eventually, a glacial horn will have near vertical faces on all sides.[ citation needed ] In the Alps, "horn" is also the name of very exposed peaks with slope inclinations of 45-60° (e.g. Kitzbüheler Horn).[ citation needed ]
A glacier is a persistent body of dense ice that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as crevasses and seracs, as it slowly flows and deforms under stresses induced by its weight. As it moves, it abrades rock and debris from its substrate to create landforms such as cirques, moraines, or fjords. Although a glacier may flow into a body of water, it forms only on land and is distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.
At all geography and geology, a cliff or rock face is an area of rock which has a general angle defined by the vertical, or nearly vertical. Cliffs are formed by the processes of weathering and erosion, with the effect of gravity. Cliffs are common on coasts, in mountainous areas, escarpments and along rivers. Cliffs are usually composed of rock that is resistant to weathering and erosion. The sedimentary rocks that are most likely to form cliffs include sandstone, limestone, chalk, and dolomite. Igneous rocks such as granite and basalt also often form cliffs.
Glaciology is the scientific study of glaciers, or, more generally, ice and natural phenomena that involve ice.
Landforms are categorized by characteristic physical attributes such as their creating process, shape, elevation, slope, orientation, rock exposure, and soil type.
A tarn is a mountain lake, pond or pool, formed in a cirque excavated by a glacier. A moraine may form a natural dam below a tarn.
An arête is a narrow ridge of rock that separates two valleys. It is typically formed when two glaciers erode parallel U-shaped valleys. Arêtes can also form when two glacial cirques erode headwards towards one another, although frequently this results in a saddle-shaped pass, called a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arête steepened through mass wasting events and the erosion of exposed, unstable rock. The word arête is French for "edge" or "ridge"; similar features in the Alps are often described with the German equivalent term Grat.
The Pirin Mountains are a mountain range in southwestern Bulgaria, with the highest peak, Vihren, at an altitude of 2,914 m (9,560 ft).
A cirque is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie and cwm. A cirque may also be a similarly shaped landform arising from fluvial erosion.
Glacial landforms are landforms created by the action of glaciers. Most of today's glacial landforms were created by the movement of large ice sheets during the Quaternary glaciations. Some areas, like Fennoscandia and the southern Andes, have extensive occurrences of glacial landforms; other areas, such as the Sahara, display rare and very old fossil glacial landforms.
A glacial lake is a body of water with origins from glacier activity. They are formed when a glacier erodes the land and then melts, filling the depression created by the glacier.
Vihren is the highest peak of Bulgaria's Pirin Mountains. Reaching 2,914 metres (9,560 ft), it is Bulgaria's second and the Balkans' third highest, after Musala and Mount Olympus. Although Vihren is deprived of lakes and streams due to the karst topography, a number of Pirin's lakes are located around the peak, as is Europe's southernmost glacial mass, the Snezhnika glacieret. Until 1942 Vihren was known as Eltepe ; it was also called Buren (stormy) and Malnienosets (lightning-bringer). The UNESCO World Heritage Site Pirin National Park was originally known as the Vihren National Park. Vihren is included in the 100 Tourist Sites of Bulgaria under No. 2.
The Cathedral Group is the group of the tallest mountains of the Teton Range, all of which are located in Grand Teton National Park in the U.S. state of Wyoming. The Cathedral Group are classic alpine peaks, with pyramidal shapes caused by glacial motion. The highest peak in the group is Grand Teton, which rises more than 7,000 feet (2,100 m) above Jackson Hole valley, and is the second tallest mountain in Wyoming, after Gannett Peak. The Cathedral Group is separated from other tall peaks of the range by the Cascade Canyon to the north and Avalanche Canyon to the south.
Mount Jarvis is an eroded shield volcano and stratovolcano in the Wrangell Mountains of eastern Alaska. It is located in Wrangell-Saint Elias National Park about 10 miles (16 km) east of the summit of Mount Wrangell. The mountain sits at the northeastern edge of the massive ice-covered shield of Wrangell, rising nearly 5,000 feet (1,500 m) above it in a spectacular series of cliffs and icefalls.
Ice Peak is the prominent south peak of Mount Edziza in Cassiar Land District of northwestern British Columbia, Canada. It has an elevation of 2,500 metres and protrudes through Mount Edziza's ice cap, which is roughly 70 square kilometres in area. The peak is a pyramid-shaped horn formed by glacial erosion and is completely flanked by steep-walled, active cirques. Tencho Glacier on the southern flank is the largest outlet glacier of Mount Edziza's ice cap. The summit of Ice Peak is about 280 metres lower than that of Mount Edziza, but it still rises well above the general level of the Big Raven Plateau. Ice Peak and the surrounding area are in Mount Edziza Provincial Park, which also includes the Spectrum Range to the south.
The Pastoruri glacier is a cirque glacier, located in the southern part of the Cordillera Blanca, part of the Andes mountain range, in Northern Peru in the Ancash region. It is one of the few glaciers left in the tropical areas of South America.
Wheeler Peak Glacier is a glacier situated at the base of Wheeler Peak within Great Basin National Park in the U.S. state of Nevada. It is the only glacier in the state, and one of the southernmost glaciers in the United States. At a height of 13,063 feet (3,982 m), Wheeler Peak is the tallest mountain in the Snake Range and the second tallest mountain in Nevada. The mountain top is also considered to be a horn, a peak carved and shaped by glaciers over a long period of time.
Snezhnika is a glacieret in the Pirin Mountains of Bulgaria, a remnant of the former Vihren Glacier. The glacieret lies at an elevation between 2,425 m (7,956 ft) and 2,480 m (8,140 ft) in the deep Golemiya Kazan cirque at the steep northern foot of Vihren, Pirin's highest summit. Due to the relatively easy access and its location along a popular hiking trail, Snezhnika is Bulgaria's most famous glacieret. Snezhnika has an average area of 0.01 km2 (0.0039 sq mi) and in 2006 it had a volume of 30,000 m3 (1,100,000 cu ft).
The southernmost persistent glacial masses in Europe are mainly small glaciers, glacierets, and perennial firn fields and patches, located in the highest mountains of the three big southern European peninsulas - the Balkan, the Apennine, and the Iberian, the southernmost ranges of the Alps and the glaciers on the european northwestern slopes of the Greater Caucasus mountains in Russia. There are summer lasting snow patches in Sierra Nevada, in Mount Olympus (40°05′08″), in Mount Korab (41°47′28″), in Rila Mountain, in Picos de Europa (43°11′51″) in the Cantabrian Mountains, in Mount Maglić (43°16′52″) and others. However, none of them have both persistency and indications of dynamic motion. In southern direction, some 4000 km away, are the glaciers in Africa in Rwenzori Mountains (00°23′09″N), Mount Kenya (00°09′03″S) and Mount Kilimanjaro (03°04′33″S).
A glacieret is a very small glacier, with a surface area less than 0.1 km2. The term is sometimes incorrectly used to refer to a large, persistent snow patch of firn or névé.
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