Processes and landforms of erosion Flashcards
(16 cards)
What are the interconnected geomorphic processes that form landforms?
Weathering, mass movement, wave erosion, fluvial erosion, aeolian erosion
These processes interact to shape various landforms such as bays, cliffs, and caves.
Define weathering in the context of geomorphology.
Erosion of Earth’s surface due to atmospheric temperature changes and precipitation
Includes chemical, physical, and biological weathering.
What is chemical weathering?
Dissolving rock surfaces predominantly with mildly acidic precipitation
This process alters the chemical composition of rocks.
What is physical weathering?
Exerting mechanical stress in geological weaknesses through extreme temperatures or crystallisation
It breaks rocks without changing their chemical composition.
What is biological weathering?
Weathering primarily due to plant growth and root expansion in geological weaknesses
Roots can penetrate rocks, causing them to break apart.
What is mass movement?
Downhill movement of a large volume of material (rock, soil, and water) due to gravity
Triggered by weathering and surface saturation.
List the types of mass movement.
- Rockfalls
- Landslides
- Slumps
Each type differs in material and angle of movement.
How do waves cause marine erosion?
Through wave pounding, hydraulic action, attrition, abrasion, and solution
These processes involve the physical impact and chemical interaction of water with land.
What is aeolian erosion?
Erosion caused by wind
This process shapes landforms like dunes and sediment beaches.
What role do rivers play in fluvial erosion?
Rivers transport sediment to the coast, where it can be deposited or eroded by waves
Most material is eroded from upstream riverbanks.
Define shore platforms.
Relatively flat intertidal surfaces formed from retreating cliffs with resistant lower strata
They are formed by the erosion of less resistant geology.
What creates a system of headlands and bays?
Discordant geology in the coastal zone
Less resistant geology erodes faster, while more resistant geology forms headlands.
How are coastal caves formed?
As wave energy impacts joints and cracks in the intertidal cliff face
They typically form in more resistant geology.
What happens to a cave that penetrates through a headland?
It begins to form an arch that widens with continued erosion
Eventually, the arch collapses to form a standalone stack.
Define geos.
Narrow and deep clefts in the face of a cliff, formed by erosion processes acting on a vertical fault or joint
They are typically found in more resistant geology.
What are blow holes?
Deep caves recessed into cliff faces that connect to the top of the cliff
They allow water entering the cave to spray upwards.
