Ch 05 - Geomorphic Processes11th Fundamentals of Physical Geography
The Two Opposing Geomorphic Forces
Why is the earth's crust geomorphologically described as a 'playfield' of two continuously opposing forces?
Why is the earth's crust geomorphologically described as a 'playfield' of two continuously opposing forces?
The Dynamic Balance of the Crust
- Endogenic Forces (Internal): These are land-building forces. Driven by the earth's internal heat, they continuously elevate or build up parts of the earth's surface through tectonics and volcanism.
- Exogenic Forces (External): These are land-wearing forces. Driven by solar energy and gravity, they continuously wear down (degrade) elevated relief and fill up (aggrade) basins.
- Conclusion: The uneven surface of the earth is the temporary result of the perpetual interaction between these internal constructive forces and external destructive forces.
Prism Memory Hook
Endogenic Enhances height; Exogenic Excavates/Erodes.
Energy Sources for Geomorphic Processes
What are the primary sources of energy that drive Endogenic and Exogenic geomorphic processes?
What are the primary sources of energy that drive Endogenic and Exogenic geomorphic processes?
Sources of Geomorphic Energy
- Endogenic Processes: Driven by energy emanating from within the earth. This includes radioactivity, rotational and tidal friction, and primordial heat leftover from the earth's formation.
- Exogenic Processes: Driven primarily by energy from the Sun (which powers the atmosphere, climate, and water cycle) and Gravity (which pulls materials downslope).
Prism Memory Hook
Endo from the Core; Exo from the Sun and Gravity.
Gravitational vs. Molecular Stress
What is the difference between Gravitational stress (Shear Stress) and Molecular stress in breaking down earth materials?
What is the difference between Gravitational stress (Shear Stress) and Molecular stress in breaking down earth materials?
Macro vs. Micro Stresses
All earth materials are subjected to physical stress (force applied per unit area):
- Gravitational Stress (Macro): Caused by the weight of overburden or gravity acting on a slope. It creates Shear Stress, which pushes materials along their faces, leading to angular displacement, faulting, and massive slippage (like landslides).
- Molecular Stress (Micro): Caused by temperature fluctuations or crystallization. It creates internal stress within the rock's minerals, leading to grain-by-grain disintegration (like weathering).
Prism Memory Hook
Gravitational causes Slips; Molecular causes Splits.
Also in this chapter
50 more cards to study in Prism
- 4Geomorphic Process vs. Geomorphic Agent
- 5Climatic Control on Exogenic Processes
- 6The Concept of Gradation
- 7Volcanism vs. Volcano
- 8Diastrophism
- 9Orogenic vs. Epeirogenic Processes
- 10Diastrophism and Metamorphism
- 11Concept of Denudation
- 12Weathering as an In-situ Process
- 13Interdependence of Weathering Processes
- 14Climatic Conditions for Chemical Weathering
- 15Chemical Weathering: Solution
- 16Chemical Weathering: Carbonation
- 17Chemical Weathering: Hydration
- 18Hydration vs. Hydrolysis
- 19Oxidation vs. Reduction
- 20Physical Weathering: Thermal Expansion
- 21Physical Weathering: Frost Wedging
- 22Physical Weathering: Salt Crystallisation
- 23Unloading and Exfoliation Domes
- 24Exfoliation: Process or Result?
- 25Weathering Landforms: Tors
- 26Biological Weathering
- 27Economic Significance: Ore Enrichment
- 28Weathering as the Base of Biodiversity
- 29The Mechanism of Mass Movements
- 30Activators of Mass Movements
- 31Classification of Mass Movements
- 32Slow Movements: Soil Creep
- 33Slow Movements: Solifluction
- 34Rapid Movements: Earthflow vs. Mudflow
- 35Volcanic Mass Wasting: Lahar
- 36Rapid Movements: Debris Avalanche
- 37Landslides: Slump
- 38Landslides: Debris Slide vs. Rockslide
- 39Case Study: Himalayas vs. Western Ghats Landslides
- 40Erosion and Kinetic Energy
- 41Deposition: The Loss of Energy
- 42Concept of Pedogenesis
- 43The 5 Factors of Soil Formation
- 44Active vs. Passive Soil Factors
- 45Soil Factors: Parent Material
- 46Soil Factors: Topography (Relief)
- 47Soil Factors: Climate
- 48Climatic Impact: Desilication
- 49Climatic Impact: Calcification (Kankars)
- 50Biological Activity: Humus Formation
- 51Biological Activity: Nitrogen Fixation
- 52Soil Factors: Time and Maturity
- 53Applied Pedogenesis: Tundra Soils
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