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Questions and Answers
What geological feature is formed when the arch of a coastal rock structure collapses?
Which process primarily leads to the formation of a beach?
What distinguishes a shingle beach from a sand beach?
Which of the following is NOT a characteristic of a beach?
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How does a spit form?
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What is the term for a spit that has a curved end?
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Which coastal feature forms when spits join two headlands together?
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What usually forms in the area behind a spit?
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What impact does sea level rise have on fresh water bodies near the coast?
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Which coastal area experienced an increase in flooding events from 1995 to 2014?
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What percentage of Bangladesh's land would be lost with just a 0.3m rise in sea level?
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What is a characteristic of low-energy coastlines?
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Which of the following is NOT a consequence of coastal erosion?
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What are raised beaches formed from?
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What indicates a positive sediment budget at a coastline?
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Which coastal area is projected to have the highest flood costs by 2050?
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How are sediment cells characterized?
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What feature is formed when sea level rises and partially submerges river valleys?
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Which process involves the compression of air in cracks of cliffs by waves?
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What happens during cavitation in coastal erosion?
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What happens to the coastal ecosystems as a result of increased storms and erosion?
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Which of the following is NOT a way waves erode the coastline?
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What contributes to the formation of estuaries in coastal systems?
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What is a primary characteristic of abrasion in coastal erosion?
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What characterizes the depth of fjords compared to other coastal landforms?
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Which statement about the processes affecting coastal landscapes is accurate?
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How are dalmatian coastlines formed?
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What factors influence the selection of areas for coastal management?
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What impact can a change in coastal processes have on landforms?
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What is meant by 'relict landforms' in coastal landscapes?
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What depth can notable fjords like Sognefjorden reach?
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How do coastal landscapes change over time?
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What is a potential disadvantage of using gabions for coastal protection?
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Groynes are effective at trapping material transported by what process?
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Which feature of breakwaters can also act as a pedestrian walkway?
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Why might the placement of a groyne be crucial?
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What is one ecological concern associated with breakwaters?
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Tidal barriers are particularly useful for managing what natural phenomenon?
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Which of the following is a drawback of using groynes?
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What is the primary purpose of riprap in coastal management?
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Study Notes
Coastal Dynamics
- Low-energy coastlines are often shielded by coral reefs or islands, resulting in fewer wave impacts.
- These coastlines feature salt marshes and tidal mudflats, where sediment accumulation exceeds erosion, promoting land growth.
- Coastal sediment inputs arise from river sedimentation, sea level rise forming estuaries, cliff erosion, and marine organism shell degradation.
- The sediment budget assesses sediment balance: a positive budget indicates land extension, while a negative budget shows coastline retreat.
Sediment Cells
- The coastline is segmented into sediment cells, which balance erosion and deposition.
- Sub-cells exist with specific material inputs and defined boundaries like headlands; theoretically, these operate as closed systems, but practical transfers may occur.
Erosion Processes
- Erosion occurs through various mechanisms:
- Abrasion: Wave-transported materials grind against coastal structures.
- Hydraulic Action: Waves compress air in cliff cracks, expanding pressure causes rock breakage.
- Cavitation: The release of compressed air from waves further erodes rock.
- Wave Quarrying: The force of waves detaches rock pieces from cliffs.
Coastal Landforms
- Beaches form from constructive wave action depositing sand or shingle.
- Shingle Beaches: Steep and narrow, composed of larger particles.
- Sand Beaches: Wide and flat, made from smaller particles.
- Distinctive beach features include:
- Berms: Ridges marking the high-tide line.
- Runnels: Sand grooves parallel to the shore.
- Cusps: Crescent-shaped markings on mixed beaches.
Spits and Bars
- Spits: Sand and shingle formations extending into the sea due to shifting coastal directions, with variations like simple, recurved, and compound spits.
- Offshore Bars: Form as materials accumulate in shallow areas, sometimes creating lagoons behind.
Impacts of Climate Change
- Increasing storm frequency and intensity heightens risks to coastal ecosystems and infrastructures.
- Rising sea levels lead to severe flooding, exemplified by Kings Point, NY, experiencing doubling flood events within a decade.
- Projected land loss includes significant areas in Bangladesh and the Maldives with minimal sea level rise.
- Saltwater intrusion threatens freshwater resources and agricultural viability, necessitating increased flood protection funding.
Coastlines of Emergence
- Sea level fall unveils new landforms:
- Raised Beaches: Higher-level beaches developed from sediment accumulation.
- Wave-Cut Platforms: Exposed surfaces from eroded former shorelines.
- Relict Cliffs: Vegetative recovery of formerly coastal cliffs.
Coastlines of Submergence
- Sea level rise results in submerged landscapes:
- Rias: Partially submerged river valleys.
- Fjords: Drowned glacial valleys with steep cliffs.
- Dalmatian Coastlines: Parallel islands formed by rising sea levels flooding valleys.
Coastal Management Techniques
- Coastal management aims to mitigate erosion and flooding impacts on populations and environments, often prioritizing urban areas for resource allocation.
- Riprap: Large rocks placed along shores to absorb wave energy, economically viable but may restrict access.
- Groynes: Structures installed to capture drifted materials, wider beaches offer better protection but can lead to downstream erosion.
- Breakwaters: Built offshore to reduce wave energy and protect coastlines, but can incur ecological costs.
- Tidal Barriers: Mechanisms across river estuaries prevent floodwaters during storms, enhancing community resilience.
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Description
Explore the dynamics of low-energy coastlines influenced by coral reefs and islands. This quiz covers sediment sources, deposition, and coastal erosion processes. Test your knowledge on how these factors shape coastal systems.