Geomorphic Processes and Earth Movements
Geomorphic
Process
The formation
and deformation of landforms on the surface of the earth are a continuous
process which is due to the continuous influence of external and internal
forces.
The internal and external forces causing stresses and chemical action on earth materials and bringing about changes in the configuration of the surface of the earth are known as geomorphic processes.
Endogenic Forces
These are internal processes that derive their energy from within the Earth, mainly from tectonic and volcanic activity.
Tectonic Processes:
Exogenic Forces
Exogenic forces can take the form of weathering, erosion, and deposition. Weathering is the breaking of rocks on the earth’s surface by different agents like rivers, wind, sea waves and glaciers. Erosion is the carrying of broken rocks from one place to another by natural agents like wind, water, and glaciers.
The actions of exogenic forces result in wearing down (degradation) of relief/elevations and filling up (aggradation) of basins/ depressions, on the earth’s surface. The phenomenon of wearing down of relief variations of the surface of the earth through erosion is known as gradation.
These are external processes driven by forces like gravity, water, wind, and ice, which gradually wear down the Earth’s surface.
- Endogenic forces are those internal forces that derive their strength from the
earth’s interior and play a crucial role in shaping the earth’s crust.
- Examples – mountain-building forces, continent-building forces, earthquakes, volcanism etc.
- The endogenic forces are mainly land-building forces.
These are internal processes that derive their energy from within the Earth, mainly from tectonic and volcanic activity.
Tectonic Processes:
- Folding: When
Earth’s crust is compressed, it bends and forms folds, leading to the
creation of mountain ranges, such as the Himalayas.
- Faulting: When the
crust is subjected to stress, it may fracture, creating faults. Movements
along these faults can result in earthquakes, forming rift valleys or blocking
mountains.
- Volcanism: The
movement of molten rock (magma) from beneath the Earth’s surface to above
it, leading to the formation of volcanic landforms like volcanoes, lava
plateaus, and volcanic islands.
Exogenic Forces
Exogenic forces can take the form of weathering, erosion, and deposition. Weathering is the breaking of rocks on the earth’s surface by different agents like rivers, wind, sea waves and glaciers. Erosion is the carrying of broken rocks from one place to another by natural agents like wind, water, and glaciers.
The actions of exogenic forces result in wearing down (degradation) of relief/elevations and filling up (aggradation) of basins/ depressions, on the earth’s surface. The phenomenon of wearing down of relief variations of the surface of the earth through erosion is known as gradation.
These are external processes driven by forces like gravity, water, wind, and ice, which gradually wear down the Earth’s surface.
(A) Weathering:
(a) Physical Weathering: The mechanical breakdown of rocks into smaller pieces without changing their chemical composition, often due to temperature changes (freeze-thaw cycles), pressure release, or biological activity.
(b) Chemical Weathering: The decomposition of rocks due to chemical reactions, often involving water, acids, or gases. This process leads to the formation of features like karst landscapes (e.g., limestone caves).
(c) Biological Weathering: The breakdown of rocks by living organisms, such as plants and microbes, which can accelerate both physical and chemical weathering processes.
(a) Physical Weathering: The mechanical breakdown of rocks into smaller pieces without changing their chemical composition, often due to temperature changes (freeze-thaw cycles), pressure release, or biological activity.
(b) Chemical Weathering: The decomposition of rocks due to chemical reactions, often involving water, acids, or gases. This process leads to the formation of features like karst landscapes (e.g., limestone caves).
(c) Biological Weathering: The breakdown of rocks by living organisms, such as plants and microbes, which can accelerate both physical and chemical weathering processes.
(B) Erosion: The
process of wearing away and transporting rock material by natural agents
like water, wind, ice, and gravity.
(a) Fluvial Erosion: Erosion caused by rivers and streams, leading to the formation of valleys, canyons, and deltas.
(b) Aeolian Erosion: Wind-driven erosion, which shapes features like dunes and desert pavements.
(c) Glacial Erosion: The movement of glaciers erodes the underlying rock, creating U-shaped valleys, fjords, and moraines.
(a) Fluvial Erosion: Erosion caused by rivers and streams, leading to the formation of valleys, canyons, and deltas.
(b) Aeolian Erosion: Wind-driven erosion, which shapes features like dunes and desert pavements.
(c) Glacial Erosion: The movement of glaciers erodes the underlying rock, creating U-shaped valleys, fjords, and moraines.
(C) Mass Wasting: The movement of rock and soil downslope under the influence of gravity, including landslides,
rockfalls, and debris flows.
(D) Deposition: The accumulation of sediment in new locations, creating landforms such
as deltas, alluvial fans, dunes, and glacial moraines.
