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The south-west coast of South Africa is a dynamic shoreline - NSC Marine Sciences - Question 4 - 2024 - Paper 1
Question 4
The south-west coast of South Africa is a dynamic shoreline. It experiences strong wave action that creates unique coastal formations. Smitswinkelbaai Cave (indicate... show full transcript
Worked Solution & Example Answer:The south-west coast of South Africa is a dynamic shoreline - NSC Marine Sciences - Question 4 - 2024 - Paper 1
Step 1
Describe TWO types of erosive forces.
Answer
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Hydraulic Action: This occurs when water and air force their way into cracks and openings in rocks. As waves crash against the shoreline, the impact can create pressure that forces water into these fissures, eventually leading to the breakdown of the rock.
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Abrasion: This process involves the wearing away of rocks and sediments as they are scraped against one another. The movement of materials, driven by waves or currents, erodes larger rocks into smaller pieces over time.
Step 2
Explain the formation AND characteristics of a wave-cut platform.
Answer
Wave-cut platforms form as a result of coastal erosion. The process begins with waves eroding the base of a cliff, leading to a notch. Over time, as the cliff continues to be eroded, it eventually collapses, leaving a flat area known as a wave-cut platform behind.
Characteristics:
- They often feature visible layers and may have pools left behind from receding water.
- The rock is typically harder and may have a slight incline extending from the cliff face to the sea.
Step 3
Compare the structure AND effectiveness of both revetments and rock armour that are recommended to be used in this expansion.
Answer
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Revetments: These are sloped structures placed on coastal regions to protect against wave action. They are often made from concrete or wooden facings and aim to stabilize the area behind them. They work by dissipating wave energy as water hits the structure, which helps protect the land behind from erosion.
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Rock Armour: Rock armour consists of large boulders placed along the coast to absorb wave energy. Unlike revetments, they remain in place even under severe conditions. The size and weight of the boulders are crucial, as they help slow down the force of incoming waves, reducing the risk of flooding.
Effectiveness Comparison:
- Revetments are effective in protecting against moderate wave action but might not withstand severe storms, while rock armour offers greater resilience due to its mass.
- Revetments can alter natural landscapes more significantly than rock armour, which can blend more seamlessly into the natural environment.
Step 4
Discuss the evidence of early humans found in and alongside Smitswinkelbaai Cave AND discuss whether environmental impact assessment (EIA) would have relevance for this archaeological site.
Answer
Evidence found in Smitswinkelbaai Cave includes various artefacts such as mollusc shells, indicating that early humans relied on marine resources. These shells reflect a diverse diet and suggest sophisticated hunting and gathering strategies.
An Environmental Impact Assessment (EIA) is crucial in this context, as it can determine how proposed developments affect both the archaeological site and the surrounding ecosystem. By assessing potential impacts and recommending mitigation strategies, an EIA helps ensure that archaeological sites are preserved for future generations while balancing developmental needs.