Coastal Landscapes and Processes - EQ1 Lecture Notes

Introduction

• Purpose: Review of EQ1 focusing on coastal landscapes and processes that cause differences.
• Note: This complements lessons, serving as a revision summary.

The Littoral Zone

• Definition: Breakwater area nearest to the coast affected by tides.
• Sections:
  • Offshore: Deep water where waves begin to break.
  • Nearshore: Shallow area, friction between waves and seabed increases.
  • Foreshore: Between high and low tides.
  • Backshore: Above high tide, affected during storms.

Types of Coastlines

• Rocky/Cliff Coastlines: High relief, resistant rock, high energy, erosion > deposition.
• Sandy Coastlines: Low relief, soft rock, deposition > erosion, constructive waves.
• Estuarine Coastlines: Salt marshes, low energy, deposition > erosion.

Dynamic Equilibrium

• Definition: Balance of sediment input, output, and energy.
• Influences: Sea level changes, tides, wave energy, weather.

Classification of Coasts

• Short-Term:
  • Tides and Currents: Energy inputs like ebbs and flows.
  • Sediment Inputs: Erosion and deposition rates.
• Long-Term:
  • Geology (Lithology): Rock type and structure affect coastline type.
  • Concordant vs. Discordant: Rock orientation relative to the sea.

Examples of Coasts

• Rocky Coasts: Resistant rocks, high energy erosion, little deposition.
• Sandy Plains: Low energy, high deposition, often wetlands or salt marshes.

Coastal Structures and Influences

• Concordant Coastlines: Rock runs parallel to sea.
• Discordant Coastlines: Perpendicular rock bands, leads to bays and headlands.

Rock Structure Influences

• Faults and Joints: Affect erosion rates, create fault lines.
• Fissures: Deep, open ravines in rock.
• Folding: Bends in rock, affects erosion and profiles.

Rock Types and Erosion

• Igneous Rocks: Slow erosion, interlocking crystals.
• Metamorphic Rocks: Resistant but less than igneous.
• Sedimentary Rocks: Least resistant, moderate erosion.
• Unconsolidated Sediment: Easily eroded.

Vegetation's Role

• Function: Stabilizes soil, protects from erosion.
• Pioneer Plants: First to colonize, stabilize the environment.

Succession Processes

• Sand Dune Succession (Psammosere): From embryo dunes to mature dunes and forest.
• Salt Marsh Succession (Halosere): Formation through mixing of fresh and sea water.

Conclusion

• Review Strategy: Focus on sand dune and salt marsh succession, rock lithology basics.
• Next Topic: EQ2 - Characteristics of coastal landforms.