An arête ( ; ) is a narrow

ridge A ridge is a long, narrow, elevated geomorphologic landform, structural feature, or a combination of both separated from the surrounding terrain by steep sides. The sides of a ridge slope away from a narrow top, the crest or ridgecrest, wi ...

of rock that separates two

valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

s. It is typically formed when two

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, 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 ...

s 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 The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

are often described with the German equivalent term ''Grat''. Where three or more cirques meet, a

pyramidal peak 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 o ...

is created.

Cleaver

Clouds Rest with Half Dome in the background

A cleaver is a type of arête that separates a unified flow of glacial ice from its uphill side into two glaciers flanking, and flowing parallel to, the ridge, analogous to an exposed mid-channel bar in a braided river. Cleaver gets its name from the way it resembles a meat cleaver slicing meat into two parts. A common situation has the two flanking glaciers melting to their respective ends before their courses can bring them back together; the exceedingly rare analogy to which is a situation of two branches of a braided river drying up before recombining. The location of a cleaver is often an important factor in the choice of climbing routes. For example, following a cleaver up or down a mountain may avoid travelling on or under an unstable glacial, snow, or rock area. This is usually the case on those summer routes to the summit whose lower portions are on the south face of Mount Rainier, where climbers traverse the flats of Ingraham Glacier but ascend Disappointment Cleaver and follow its ridgeline rather than ascend the headwall either of that glacier or (on the other side of the cleaver) of Emmons Glacier.

Examples

Notable examples of arêtes include: * Beenkeragh Ridge, MacGillycuddy's Reeks, County Kerry, Ireland. * The Carn Mor Dearg arête on to Ben Nevis, Scotland * Clouds Rest, in the Sierra Nevada,

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

* Crib Goch, in Snowdonia National Park, Wales * The Garden Wall, in Glacier National Park,

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

(image to right) * Matthes Crest, in

Yosemite National Park Yosemite National Park ( ) is a List of national parks of the United States, national park of the United States in California. It is bordered on the southeast by Sierra National Forest and on the northwest by Stanislaus National Forest. The p ...

, California * Knife Edge, in Baxter State Park, Maine * Koncheto, Pirin mountain,

Bulgaria Bulgaria, officially the Republic of Bulgaria, is a country in Southeast Europe. It is situated on the eastern portion of the Balkans directly south of the Danube river and west of the Black Sea. Bulgaria is bordered by Greece and Turkey t ...

* Mazeno Ridge,

Gilgit-Baltistan Gilgit-Baltistan (; ), formerly known as the Northern Areas, is a region administered by Pakistan as an administrative units of Pakistan, administrative territory and consists of the northern portion of the larger Kashmir region, which has b ...

, Pakistan * The Minarets, in the Sierra Nevada, California * The Sawtooth, in the Southern Rocky Mountains * Strazhite (The guardians), Pirin mountain,

* Striding Edge in the English

Lake District The Lake District, also known as ''the Lakes'' or ''Lakeland'', is a mountainous region and National parks of the United Kingdom, national park in Cumbria, North West England. It is famous for its landscape, including its lakes, coast, and mou ...

* Trionite (The Saws),

Rila Rila (, ) is the highest mountain range of Bulgaria, the Balkans, Balkan Peninsula, and Southeast Europe. It is situated in southwestern Bulgaria and forms part of the Rila–Rhodope Mountains, Rhodope Massif. The highest summit is Musala at an e ...

mountain,

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Diagram

{{DEFAULTSORT:Arete Geographical terminology in mountaineering Glacial erosion landforms Ridges Oronyms

Cleaver

Examples

See also

References

Sources

External links