What is Arete?
Arete Definition Geography
A narrow ridge of rock that separates two valleys is known as an arête. It is typically formed when two parallel U-shaped valleys are eroded by glaciers. A horn is formed when glaciers erode three or more aretes, resulting in a sharp-edged peak.
Aretes can also form when two glacial cirques erode headward towards each other, though this usually results in a saddle-shaped pass known as a col. The edge is then sharpened by freeze-thaw weathering, and the slope on either side of the arête is steepened by mass wasting and erosion of exposed, unstable rock.
Hence, we can say that the Arete glacier consists of horns and serrated ridges which are formed by glacial erosions.
The term 'arete' actually refers to a ridge or edge in French; similar features in the Alps are often described with the German equivalent term Grat.
A pyramidal peak is formed when three or more cirques intersect.
Arete Glacier Type: Cleaver
A cleaver is a type of arete that divides a unified flow of glacial ice from its uphill side into two glaciers flanking the ridge and flowing parallel to it. The name Cleaver comes from the way it resembles a meat cleaver slicing meat into two pieces. A cleaver can be compared to an island in a river.
A common scenario involves two flanking glaciers melting to their respective ends before their courses can reconnect them; an extremely rare analogy involves two branches of a river drying up before the downstream tip of the island due to evaporation or absorption into the ground.
The location of a cleaver is frequently a deciding factor in the choice of glacier flow routes. For example, following a cleaver up or down a mountain will help you avoid travelling on or through an unstable glacial, snow, or rock field.
This is typically the case on summer routes to Mount Rainier's summit that traverse the 'flats' of Ingraham Glacier, but ascend Disappointment Cleaver and follow its ridgeline rather than ascending the headwalls of either that glacier or Emmons Glacier (on the other side of the cleaver).
FAQs on Arete
Q1. Is Arete an Erosion or Deposition?
Ans. Glaciers erode by plucking and abrasion. Valley glaciers create several distinct features through erosion, such as cirques, arêtes, and horns.
Q2. What are Glaciers?
Ans. Glaciers are massive flows of ice. They now cover only about 10% of the Earth's surface. As the Earth's temperature rises, they become smaller and smaller. However, glaciers dipped as far south as Chicago and New York City only 12,000 years ago. At the time, much of Europe was also covered in glaciers.
Glaciers erode, leaving behind distinct landforms. These landforms serve as hints. They show how far a glacier advances and in which direction it flowed.
Q3. What Do You Mean by Horns and Serrated Ridges?
Ans. The cirque walls erode headward, resulting in horns. They are steep-sided peaks with sharp points. They are created by the cirque wall eroding inward. Three or more radiating glaciers slash the face of the mountain until their cirques meet high, sharp-pointed, steep-sided peaks, forming horns.
The Matterhorn, the highest peak in the Alps, and Everest, the highest peak in the Himalayas, are both horns formed by the headward erosion of radiating cirques.
Because of progressive erosion, the gaps between Cirque side walls or headwalls narrow and become serrated or saw-toothed ridges, also known as aretes, with a sharp crest and zig-zag outline. Ridges are also known as hills or mountains, depending on their height.
