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Surface Processes Answer (i) or (ii) - Leaving Cert Geography - Question B - 2015
Question B
Surface Processes Answer (i) or (ii). (i) Explain, with the aid of diagrams, the formation of any two landforms. or (ii) Describe and explain any two processes o... show full transcript
Worked Solution & Example Answer:Surface Processes Answer (i) or (ii) - Leaving Cert Geography - Question B - 2015
Step 1
Explain, with the aid of diagrams, the formation of any two landforms.
Answer
To explain the formation of two landforms, we will discuss the processes involved in the formation of a glacier (as a landform) and a river delta.
Glacier Formation
A glacier is formed through the accumulation and compaction of snow over long periods. The following steps detail this process:
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Snow Accumulation: In high-altitude regions, snow accumulates in layers over time, especially in areas where snowfall exceeds melting.
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Compaction: As more snow accumulates, the lower layers become denser. Pressure compacts the snow into firn (granular snow) and eventually into glacial ice.
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Movement: The glacier then moves under its weight, flowing slowly down valleys. This movement is driven by gravity and can carve the landscape, forming U-shaped valleys.
Diagram of Glacier Formation
- Layered Snow Accumulation
- Cross-section showing Ice Layers
- U-shaped Valley from Glacial Movement
River Delta Formation
A river delta is formed at the mouth of a river, where it meets a body of water, such as an ocean or a lake. The process involves:
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Sediment Transportation: Rivers erode rocks and soil upstream, transporting sediment downstream.
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Deposition: As the river slows upon entering standing water, it loses energy and deposits sediment, forming layers over time.
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Landform Development: Continued deposition can create a delta characterized by distributaries and swampy areas.
Diagram of River Delta Formation
- Flow of River into Ocean
- Sediment Deposition in Layers
- Spread of Delta Front
This methodical process results in significant landforms that are crucial for aquatic ecosystems.
Step 2
Describe and explain any two processes of mass movement.
Answer
Mass movement refers to the downhill movement of soil and rock under the influence of gravity. We will describe two processes: landslides and creep.
Landslides
A landslide is a sudden and fast movement of a large amount of earth material, typically triggered by factors such as heavy rainfall, earthquakes, or human activities.
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Process Name: Landslide
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Description and Explanation:
- Triggering Factors: Intense rain saturates soil, reducing its cohesion. Earthquakes can destabilize slopes, leading to rapid movement.
- Types: Rockslides are common during landslides, where surface materials flow quickly down a slope.
- Impact: Landslides can cause destruction to property and habitat, and pose severe risks to nearby communities.
Example
- A notable incident of a landslide occurred in the 2014 Oso landslide, resulting in significant loss of life and property.
Creep
Soil creep is a slow, gradual movement of soil and rock just below the surface.
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Process Name: Creep
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Description and Explanation:
- Slow Movements: Creep occurs over long periods and is often imperceptible in the short term, but over decades can significantly alter landscapes.
- Causes: Factors include freeze-thaw cycles, wetting and drying of soil, and plant root growth causing expansion and contraction.
- Characteristics: Signs of creep include tilted trees, cracks in pavement, or displaced walls.
Example
- Creep is often observed in hilly areas where structures show sign of leaning and cracking due to the slow movement of underlying soil.