Q 1 – What is geomorphology?
Ans. It is the study of landforms especially concerned with the genesis, evolution, and processes involved in the formation of the surface features of the earth.
Q 2 – What is the relief?
Ans. The physical landscape of the earth’s surface is called relief. It includes mountains, valleys, plains, and plateaus.
Q 3 – Name various types of weathering.
Ans. Chemical weathering, mechanical weathering, and biological weathering.
Q 4 – Arrange the following from smaller to bigger form: stream, gully, river, rill.
Ans. Rill, gully, stream, river.
Q 5 – What is fiord?
Ans. When a glacial trough formed near the sea gets filled up by the seawater, it is called a fiord. It is a deep steep-sided water inlet near the sea.
Q 6 – What do you understand by mud-flow?
Ans. Mud-flow is a moving mass of solid waste fluid by rain or melting snow.
Q 7 – What is deflation?
Ans. Deflation is the lifting and transporting of loose particles of clay and silt, collectively referred to as dust.
Q 8 – What is a landform?
Ans. The landform is the shape, focus and volume of a specific physical feature of the earth’s surface produced by natural processes of erosion and deposition.
Q 9 – What is the combination?
Ans. A combination is a form of chemical weathering caused due to the reaction of minerals with dissolved carbon dioxide in water.
Q 10 – Name two basic forms in which the running water acts as a geomorphic agent.
Ans. As a geomorphic agent, the running water acts in two basic forms, namely overland flow and channel or streamflow.
Q 11 – What is a drainage basin?
Ans. The drainage basin is a part of land drained by a sole river system.
Q 12 – What are three closely inter-related geomorphic works performed by rivers?
Ans. Rivers perform three closely inter-related geomorphic works, viz., erosion, transportation, and deposition.
Q 13 – Give an example of badland topography.
Ans. The valley of the Chambal in Madhya Pradesh is an example of badland topography.
Q 14 – What is Karst topography?
Ans. Karst topography is a landscape formed by groundwater in a limestond1 region.
Q 15 – What is meant by water table?
Ans. The top of the zone of saturated rocks is called the water table.
Q 16 – Why is wind action most prominent in arid and semi-arid areas?
Ans. Wind action is most prominent in arid and semi-arid areas as there are loose particles of soil in these areas and wind can remove them easily.
Q 17 – Which areas on the earth’s surface depict landforms made by glaciers?
Ans. The following areas on the earth’s surface depict landforms made by glaciers:
- High altitude areas,
- High mountain areas.
Q 18 – What is a glacier?
Ans. The moving heap of ice and snow is termed a glacier.
Q 19 – How are lagoons formed? Give two examples of lagoons from India
Ans. Lagoons are formed when sand bars along the coast cut off a portion of the sea from the main water body.
Example:
- Chilka lake (in Orissa),
- Pullicat lake (Tamilnadu).
Q 20 – Where are areas of permanent snow or ice found over the surface of the earth?
Ans.
- Areas or regions situated at high latitudes.
- Areas situated at very high altitudes irrespective of their distance from the equator.
Q 21 – What acts as cutting tools for the sea waves?
Ans. Loose pieces of rocks and sand suspended in the sea waves.
Q 22 – What is marine erosion?
Ans. Marine erosion is the erosion of rocks in the coastal areas, carried out by the sea waves.
Q 23 – Where are lagoons mostly found in India?
Ans. On the Malabar coast of India.
Q 24 – Where is the Marine beach situated in India?
Ans. Marine beach is situated in Chennai on the Coromandel coast.
Q 25 – What is the distance covered by a rapidly moving glacier in a day?
Ans. 4 kilometres per day.
Q 26 – Where is wind most important as an agent of gradation?
Ans. In arid and semi-arid regions.
Q 27 – Enumerate various forms made by wind action.
Ans.
- Wind eroded basin,
- Loess plains,
- Sand dunes.
Q 28 – Where do the sand dunes originate?
Ans. Sand dunes originate at the place where there is some obstruction in the way of the wind.
Q 29 – How would you explain the fact that the areas of permanent snow or ice are in high latitudes and very high altitudes?
Ans.
- Sun always shines perpendicular on the equator. Hence, equatorial regions get intense heat due to straight sun rays. As we go northwards or southwards from the equator, the sun’s rays become oblique and less heat is received in these regions. Hence, poles are always cold.
- Temperature decreases with increase in height at the rate of 1 °C per 165 metres height. Hence, as we go above from the equator, fewer temperatures are observed. A height comes when the temperature is below freezing point and snow and ice rules over.
Q 30 – What are snowfields? Where are they generally situated?
Ans. The vast areas which are permanently covered with snow and ice are called snowfields.
The snowfields are generally found situated above the snow line
- High latitudes and polar regions,
- Near mountain tops.
Q 31 – What is meant by ‘moraines’?
Ans. Glaciers carry pieces of rocks, big and small, with them. They deposit them at certain places – at their edges, on the bottom, at the terminals and the central zone of two glaciers. These deposits are called moraines.
Q 32 – Define loess plateau?
Ans. Loess is the deposit of sand blown over long distances and deposited over large areas. When the thickness of the loess is hundreds of metres, it assumes the name of loess plateau.
Q 33 – Write a short note on the formation of sand dunes.
Ans. Wind deposits sand brought by it as sand dunes. The major features of these sand dunes are as follows:
- A sand dune is a typical hill. It has a crest.
- It is generally mobile as it goes on shifting along the direction of the prevailing wind.
- Obstructions in the path of the wind lead to the formation of the sand dunes.
- Sand dunes vary in size. They vary from a few metres to 300 metres in height.
Q 34 – What is a fiord?
Ans. When a glacial trough formed near the sea gets filled up by the seawater, it is called a fiord. Thus a fiord is a deep, steep-sided water inlet near the sea. It is typical of Norwegian and Chilean coasts.
Q 35 – What is ‘regolith’?
Ans. Regolith is a layer of loose or soft material lying above the bedrock. When regolith is formed by decomposition and disintegration of the bedrock that lies directly beneath it, it is called residual regolith. The regolith transported by steam, ice, water and deposited elsewhere is called transported regolith.
Q 36 – Define fluvial denudation.
Ans. Running water is undoubtedly the most important agent of denudation. It is most conspicuous as a stream or river that transports enormous volumes of surplus precipitation from the land to the ocean. Stream action, in combination with weathering, mass wasting and overland flow, is responsible for the total process called fluvial denudation.
Q 37 – Explain two forms of the flow of running water as the geomorphic agent.
Ans. Running water acts as a geomorphic agent in two basic forms, viz., overland flow and channel or streamflow.
Overland flow is the movement of run-off downhill on the ground surface in a more or less broadly distributed sheet or film. Second is channel flow or streamflow in which water moves to lower levels in a long, narrow, trough-like feature called stream-channel, bounded on both sides by rising shapes called banks that contain the flow.
Q 38 – Discuss the features developed due to falling rain on bare surfaces.
Ans. Gentle rain falling on bare surfaces loosens the soil and muddies the water. The muddy water flows as the thin, slow-moving surface layer of water called sheet flow. As the slope increases, the water scours additional sediments and erodes small channels, which are called rills. Headward erosion of rills and their subsequent widening leads to gully formation. Gullies dissect the land into a number of isolated hills, giving rise to badland topography.
Q 39 – Discuss the internal and external forces involved in the creation of landforms.
Ans. A host of internal and external forces are involved in the creation of landforms. Tectonic forces crumple rocks and push up continents and mountain ranges. Moving water, air and ice erode rocks and transport the eroded debris to depositional sites and thus change the appearance of the landscape with the passage of time. The intensity of these agencies varies from one region to- another depending on climate, vegetation and altitude.
Q 40 – How is a U-shaped valley formed?
Ans. A glacier does not make its own valley. When a glacier enters a V-shaped river valley, it modifies it into a U-shaped valley. The valley is deepened as the pressure of ice increases. A wide, flat structure is formed. Due to side cutting the valley is widened, and it is known as U-shaped valley.