Exogenic Processes [Geography Notes For UPSC]
- Exogenic Processes. The exogenic processes obtain their energy from the gradients generated by tectonic factors, processes, their corresponding driving forces and atmosphere determined by the energy from the sun.
- Weathering. ...
- Mass Movements: These movements transfer the mass of rock debris down the slopes under the direct influence of gravity.
What are exogenic processes?
The processes that take place at or near the Earth’s surface are called Exogenic Processes. These processes are a part of denudation process which involves wearing away of Earth’s surface. The topic, ‘Exogenic Processes’ comes under GS-I Geography subject for IAS Exam.
What are exogenic and endogenic forces?
The exogenic forces derive their energy from the atmosphere determined by the ultimate energy from the sun and also the gradient created by tectonic factors. We have already discussed in previous articles that slopes on the earth surface are mainly created by tectonic factors or earth movements due to endogenic forces.
What are the endogenic processes?
Endogenic processes or endogenesis manifests itself through rock dynamics and rock deformation, which include flowage, mass movement , and plastic flow. All processes that move, elevate or build up portions of the earth’s crust come under diamnophism.
What are the effects of the exogenic geomorphic processes?
The effects of most of the exogenic geomorphic processes are minor and slow. It may be imperceptible in a short time span, but will in the long run influence the rocks harshly due to constant fatigue. All the exogenic geomorphic processes are covered under a general term, denudation.
What are exogenic processes?
Exogenic Processes or Denudation. The processes which occur on the earth’s surface due to the influence of exogenic forces are called exogenic processes or exogenic geomorphic processes. Weathering, mass wasting, erosion, and deposition are the main exogenic processes. All the exogenic processes are covered under a general term- denudation, ...
Where do exogenic forces get their energy?
The exogenic forces derive their energy from the atmosphere determined by the ultimate energy from the sun and also the gradient created by tectonic factors. We have already discussed in previous articles that slopes on the earth surface are mainly created by tectonic factors or earth movements due to endogenic forces.
What are the forces that derive their strength from the Earth's exterior?
The forces which derive their strength from the earth’s exterior or originate within the earth’s atmosphere are called as exogenic forces or external forces. The action of exogenic forces results in wearing down and hence they are considered as land wearing forces.
What happens when rocks undergo weathering?
When rocks undergo weathering, some minerals are removed through chemical/ physical leaching by groundwater and thereby the concentration of remaining (valuable) minerals increase. Weathering can be classified as – physical, chemical and biological:
Why do rocks have rounded edges?
Due to differential heating and the resulting expansion and contraction of surface layers and their subsequent exfoliation from the surface results in smooth rounded surfaces in rocks. In rock like granites, smooth-surfaced and rounded small to big boulders called tors form due to such exfoliation.
What is an agent in science?
An agent is a mobile medium ( like running water, moving ice, winds, waves etc) which removes, transport and deposits earth materials. Geomorphic processes and geomorphic agents especially exogenic, unless stated separately, are one and the same. Gravity and gradients are the two things that make these agents mobile.
What causes frost weathering?
Cycles of freezing and thawing (the weather becomes warmer and causes snow and ice to melt) cause frost weathering. It is most effective at high elevations in mid-latitude where freezing and melting is often repeated. Rapid freezing of water causes its sudden expansion and high pressure.
What causes the expansion and contraction of rocks?
Block disintegration A successive heating and cooling which causes the expansion and contraction of rocks. In hot desert regions, day temperatures are very high while nights are very cold. This high diurnal range of temperature causes successive expansion and contraction of the rocks which tend to enlarge the joints.
What is the process of oxidation?
Oxidation The process in which atmospheric oxygen reacts with the rock to produce oxides. The greatest impacts of this process is observed on ferrous minerals. Oxygen present in humid air reacts with iron grains in the rock to form a yellow or red oxide of iron. This is called rusting of the iron.
What is the term for the process of a rock disintegrating physically and chemically?
Weathering ▪Is the general term applied to the combined action of all processes that cause rock to disintegrate physically and decompose chemically because of exposure near the Earth’s surface through the elements of “weather” such as temperature, rainfall, frost, fog and ice.
What are the three types of weathering?
5. 3 types of Weathering (Physical, Chemical and Biotic ) 1. Physical weathering Happens whenever rocks are broken up into smaller fragments without any chemical change in their composition. This type of weathering takes place in different ways in different types of areas.
What is chemical weathering?
2. Chemical Weathering Chemical change in the rocks through formation of new compounds or formation of new substances is called chemical weathering. There are several chemical processes included such as oxidation, hydrolysis, and acid solution. 10. Types of Chemical Weathering a.
Why do rocks peel off?
Since rocks are poor conductors of heat, the inner layers remain almost un affected by heat. Due to successive expansion and contraction , the outer layers of the rock subsequently peel off from the main mass of the rock in the form of concentric shell. 8. c.
What is the process by which water is absorbed by the minerals of the rocks?
Hydration The process by which water is absorbed by the minerals of the rocks. Due to the absorption of water by the rock, its volume increases and the grains lose their shape. Feldspar, for example, is changed into kaolin through hydration. 13. d.
What are some examples of exogenous processes?
Some other examples of exogenous processes are rain, snow, hail, tsunamis, avalanches, winds, undulating currents, etc. It is a fact established and established by science that the development ...
What is endogenous process?
Endogenous processes. Also known as hypogenic processes, they are processes of internal origin. In other words, they are processes that originate within the Earth crust And are therefore called endogenous.
What is the term for the process of mutually dependent changes?
Since these processes are restricted to the surface of the Earth, they are called epigenic processes . These processes constitute a very complex sum of mutually dependent changes, that is, all exogenous processes are involved with each other.
What are the processes that occur on Earth?
The processes that are caused by forces inside the Earth are called endogenous processes. Stone arch produced by erosion. There are three main endogenous processes: folding, failure and volcanism. They occur mainly along the boundaries ...
What causes destruction products to disintegrate?
Destruction products disintegrate under the influence of gravity or are drawn by the wind blowing, flowing waters, moving glaciers, etc., to the lower areas such as lakes, seas, The oceans and so on. Exogenous processes tend to eliminate any unevenness on the surface of the Earth.
What is the process that raises the Earth's surface?
The tectonic process that leads to raising or constructing portions of the Earth's surface is called diastrophism and is what prevents the exogenous process from ultimately reducing Earth's land areas at sea level.
What are the processes of degradation?
Degradation is the process by which upland material is removed by geomorphic agents as a result of which the altitude is reduced. The degradation of the terrestrial surface is realized mainly through: 1 Resistance to the weather 2 Waste of mass 3 Erosion
Exogenic Processes
- The exogenic processes obtain their energy from the gradients generated by tectonic factors, processes, their corresponding driving forces and atmosphere determined by the energy from the sun.
- Precipitation and temperature are the two significant climatic components that regulate different processes.
- The exogenic processes obtain their energy from the gradients generated by tectonic factors, processes, their corresponding driving forces and atmosphere determined by the energy from the sun.
- Precipitation and temperature are the two significant climatic components that regulate different processes.
- Whole exogenic geomorphic processes are covered under a common term, denudation which means to uncover.
- Weathering, transportation, and erosion are comprised of denudation.
Weathering
- Weathering is defined as the mechanical disintegration and chemical decomposition of rocks through the actions of various elements of weather and climate. There are three major groups of weathering processes : (i) chemical Weathering; (ii) physical or mechanical Weathering; (iii)biological weathering
Mass Movements
- These movements transfer the mass of rock debris down the slopes under the direct influence of gravity.
- That means, air, water or ice do not carry debris with them from place to place but on the other hand the debris may carry with it air, water or ice.
- The movements of mass may range from slow to rapid, affecting shallow to deep columns o…
- These movements transfer the mass of rock debris down the slopes under the direct influence of gravity.
- That means, air, water or ice do not carry debris with them from place to place but on the other hand the debris may carry with it air, water or ice.
- The movements of mass may range from slow to rapid, affecting shallow to deep columns of materials and include creep, flow, slide and fall.
- Mass movements are aided by gravity and no geomorphic agent like running water, glaciers, wind, waves and currents participate in the process of mass movements. That means mass movements do not com...
Erosion and Deposition
- Erosion involves the acquisition and transportation of rock debris. When massive rocks break into smaller fragments through weathering and any other process.
- Erosional geomorphic agents like running water, groundwater, glaciers, wind and waves remove and transport it to other places depending upon the dynamics of each of these agents.
- Abrasion by rock debris carried by these geomorphic agents also aids greatly in erosion. By e…
- Erosion involves the acquisition and transportation of rock debris. When massive rocks break into smaller fragments through weathering and any other process.
- Erosional geomorphic agents like running water, groundwater, glaciers, wind and waves remove and transport it to other places depending upon the dynamics of each of these agents.
- Abrasion by rock debris carried by these geomorphic agents also aids greatly in erosion. By erosion, relief degrades, i.e., the landscape is worn down.
- It is erosion that is largely responsible for continuous changes that the earth’s surface is undergoing.
What Are Exogenic Forces?
Exogenic Processes Or Denudation
- The processes which occur on the earth’s surface due to the influence of exogenic forces are called exogenic processes or exogenic geomorphic processes. Weathering, mass wasting, erosion, and depositionare the main exogenic processes. All the exogenic processes are covered under a general term- denudation, which means strip off or uncovers. The ele...
Weathering
- Weathering is the action of elements of weather and climateover earth material. It can be defined as mechanical disintegration and chemical decomposition of rocks through the actions of various elements of weather and climate. When rocks undergo weathering, some minerals are removed through chemical/ physical leaching by groundwater and thereby the concentration of remainin…
Mass Movements
- These movements transfer the mass of rock debris down the slope under the direct influence of gravity. Mass movements are very active over weathered slopes rather than over unweathered slopes. Usual geographic agents like running water, glaciers, wind, waves etc do not have much role to play in mass movements, and it is gravity, which is the main driving force. Mass moveme…
Erosion and Deposition
- Erosion is the acquisition and transportation of rock debris by geomorphic agents like running water, the wind, waves etc. Though weathering aids erosion, it is not a pre-condition for erosion to takes place. (i.e., erosion can take place in unweathered conditions also) The deposition is a consequence of erosion. The erosional agents lose their velocity and energy on gentle slopes an…