Static Quiz 25 January 2023 (Geography)

Ans;- c) Both 1 and 2

Explanation;-
• Both the statements are correct regarding Outwash Plain are correct.

About Outwash Plain

• When the glacier reaches its lowest point and melts, it leaves behind a stratified deposition material, consisting of rock debris, clay, sand, gravel etc. This layered surface is called till plain or an outwash plain.
• An outwash plain, also called a sandur, sandr or sandar, is a plain formed of glacial sediments deposited by meltwater outwash at the terminus of a glacier. As it flows, the glacier grinds the underlying rock surface and carries the debris along. 
• Outwash plains and eskers form due to the flow of meltwater in front of (outwash plains) or beneath (eskers) that glacier ice. They are composed of glacial sediments that have been reworked by flowing water.
• An outwash plain is both an erosional and depositional surface created by meltwater coming from the glacier. These plains are found in front of the glaciers and are typically characterized by small braided streams.

Ans;- d) None of the above

Explanation;-

• A moraine is any accumulation of unconsolidated debris, sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice sheet. 
• A moraine is material left behind by a moving glacier. This material is usually soil and rock. Just as rivers carry along all sorts of debris and silt that eventually builds up to form deltas, glaciers transport all sorts of dirt and boulders that build up to form moraines.
• Most commonly “moraine” is used to describe ridge-shaped glacial landforms, i.e., moraine ridges, although the term also covers landforms of large spatial extent, such as subglacial till plains (ground moraines) and hummocky moraines formed by melt-out of large areas of stagnant, debris-covered glacier ice.
• Characteristics. Moraines may be composed of debris ranging in size from silt-sized glacial flour to large boulders. The debris is typically sub-angular to rounded in shape. Moraines may be on the glacier’s surface or deposited as piles or sheets of debris where the glacier has melted.

Ans;- c) Both 1 and 2

Explanation;-
• Both the staements are correct about Cirque/Corrie

• 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.
• The concave shape of a glacial cirque is open on the downhill side, while the cupped section is generally steep.
Corries form in hollows where snow can accumulate.
• The snow compacts into ice and this accumulates over many years to compact and grow into a corrie/cirque glacier.
• This then moves down hill because of gravity and the mass of the ice.

Ans;- d) All of the above

Explanation:-

• As a glacier moves over the land, it drags rock fragments, gravel and sand along with it.
• These rock fragments become efficient erosive tools.
• With their help glacier scrapes and scours the surface rocks with which it comes in contact. This action of glacier leaves behind scratches and grooves on rocks.
• The landforms like Cirque, ‘U’ shaped valley, Hanging Valley etc are created by the glacial erosion.

Ans;- c) Both 1 and 2

Explanation;-
• Both the statements are correct.

• A hanging valley is a tributary valley that is higher than the main valley. They are most commonly associated with U-shaped valleys when a tributary glacier flows into a glacier of larger volume.
• Just like tributary streams of the river, there are tributary the glaciers also which join the main glacier after moving over their mountainous path.
• These tributary glaciers like the main glaciers carve U – shaped valleys.
• However, they have less volume of ice than the main glaciers and thus their rate of erosion is less rapid.
• As a result, their valleys are smaller and not as deep as that of the main glacier.
• Due to this difference in deepening; the valley of the tributary glacier is left at a higher level than that of the main glacier.
• The val1ey of the tributary glacier just looks like hanging downwards at the point of its confluence with the main valley.
• This type of a topographical feature is cal1ed a hanging val1ey.
• This feature is visible when ice has melted in both the val1eys.
• When the ice in the hanging valley melts, a waterfall is formed at the point of confluence of this stream with the main river.