Distinctive Landscapes: Coasts

Distinctive Landscapes: Coasts

1. Introduction

Coasts are dynamic landscapes shaped by the constant interaction of land and sea. This interplay creates a variety of distinctive landforms, from towering cliffs to sandy beaches.

2. Processes of Coastal Erosion

Waves: Waves are the primary force of erosion. They gain energy from wind and exert force on the coastline through:

• Hydraulic Action: The force of water compressing air into cracks in the cliff face, causing it to break apart.
• Abrasion: The grinding action of rock fragments carried by waves against the coastline.
• Attrition: The process of rock fragments colliding with each other, becoming smaller and rounder.

Other processes:

• Weathering: The breakdown of rocks by wind, rain, and frost.
• Mass Movement: The movement of rock and soil downslope due to gravity, often triggered by heavy rain or undercutting by waves.

3. Processes of Coastal Deposition

Longshore Drift: The movement of sediment along the coastline by waves approaching the shore at an angle. This creates features such as spits and tombolos.

Deposition: The dropping of sediment, often in sheltered areas where wave energy is low.

4. Landforms of Erosion

• Cliffs: Steep slopes formed by wave erosion.
• Wave-cut Platforms: A flat surface exposed at low tide, formed by the erosion of the cliff base.
• Caves, Arches, Stacks, and Stumps: Eroded features formed by wave action concentrating on weaknesses in the rock.

5. Landforms of Deposition

• Beaches: Accumulations of sand and shingle deposited by waves.
• Spits: Narrow ridges of sand extending out from the coastline, formed by longshore drift.
• Tombolos: Sandbars connecting an island to the mainland.
• Sand Dunes: Hills of sand formed by wind action.

6. Human Impacts

• Coastal Defence: Structures like seawalls and groynes are built to protect coastlines from erosion.
• Climate Change: Rising sea levels and more extreme weather events exacerbate coastal erosion.
• Tourism: Development can have a negative impact on coastal environments.

7. The Dynamic Nature of Coasts

Coasts are constantly changing, with erosion and deposition happening simultaneously. Their shape and features are a product of these ongoing processes. Understanding these processes is crucial for managing coastal environments sustainably.