Cirque is a natural landform created as an aftermath of glacial erosion. Locals in Scotland refer to it as corrie, while in Wales, it is commonly known as a cwm. The most fascinating feature of this landform is that it looks like a half-opened amphitheatre. Cirque has steep headwalls, followed by a gentle slope and over-deepened valley floor. This natural marvel is usually found in high glaciated mountainous terrains. A lot of geological upheavals are involved in the formation of the Cirque. Keep reading on if you want to know all about the geological processes of this natural beauty.
Formation of Cirque
The size of glacial Cirques is usually measured to be 1 km long and 1 km wide. They are typically sited on high-glaciated mountains. These Cirques can be distinctly identified by their amphitheatrical look a hollow surrounded by cliffs on the three sides. Another distinct feature of the glacial Cirques is that they generally have a North or North-Eastern orientation to shelter from the sun's rays. Protection from the sun is necessary as it facilitates the accumulation of snow, which later turns into glacial ice. It must be noted that the accumulation of the glacial ice triggers glacial erosion and the formation of glacial Cirques. When the ice accumulates on the glacier, it causes glacial erosion and associated disintegration of mountain rocks, leading to avalanches that bring down more snow into the already growing polar ice. This further increases the hollow and stimulates more glacial erosion, eventually forming a bowl-shaped structure on the side of the mountain with steep headwalls. This is how the amphitheatre-like landform is formed in the snow-capped mountain regions.
Topography of Cirques
There are three major geographical topographies associated with Cirques, as described below:
Arête is a French word for ridge or edge. In terms of mountains and glaciers, Arête represents a narrow ridge separating two valleys. Typically, an Arête is formed when two glaciers erode simultaneously to form U-shaped valleys. Another significant factor influencing the formation of Arête is the headward erosion of two glacial Cirques. Specifically, this erosion results in Col, which is a saddle-shaped pass. The Arête is sharpened due to frost weathering and steepened due to mass wasting. Arête can be found in glacial Cirques of Nunataks.
As the name suggests, the Pyramidal peak is a sharply-pointed mountain peak that develops due to glacial erosion and Cirque formation. It happens when multiple Cirque glaciers diverge from a single point. This leads to the formation of a glacial horn or pyramidal peak, which is angular and pointed. The Matterhorn peak is a classic example of the pyramidal peak in the Alps Mountain range.
As can be deduced from the name, a stairway Cirque is a landform in which several Cirques are arranged in a sequential order, one above the other to form a stairway-like topography. These stairway Cirques are formed due to geo-morphodynamic processes, such as erosion. Zagster Loch is one of the best examples of a stairway Cirque. It is situated in the German Central Uplands.
Nature never ceases to amuse us. In every landform, vegetation, living being, one finds distinct beauty and magnificence. Glacial Cirques are one of the classic examples of this awe-inspiring natural magnificence. These amphitheatrical-like beauties, formed in millions of years and by a motley of geological phenomena, offer an exquisite scenic experience.
FAQs on Cirque
Q.1. What is a Cirque?
A Cirque is a U-Shaped valley, which looks like an amphitheatre as steep headwalls surround it on the three sides.
Q.2. How are glacial Cirques formed?
Glacial Cirques are formed due to glacial erosion.
Q.3. Where can one find Cirques?
Cirques are typically found in high-glaciated mountain ranges such as Central Uplands in Germany.
Q.4. What are the different topographies associated with a Cirque?
Three topographies are associated with Cirque:
- Arete: It is a ridge formed by the parallel simultaneous erosion of two glaciers.
- Pyramidal Peak: It is a sharp, angular peak formed due to the divergence of multiple glaciers from a central point.
- Stairway Cirque: In this landform, multiple Cirques are formed one above the other in the form of a stairway.