The littoral zone and classifying coasts

The littoral zone

The coast is the boundary zone where land, sea and air meet and marine and land processes interact. The wider littoral zone stretches from the land that the sea can still influence out to the shallow sea floor where waves still touch the bed.

The specification divides it into:

• Backshore: above the reach of normal high tides; only affected by storm waves (cliffs, dunes, the top of the beach).
• Nearshore (including the foreshore, the intertidal area between high and low tide): where waves break and most sediment moves.
• Offshore: beyond the breaking waves, where waves still affect the bed but deposition dominates.

The littoral zone is dynamic: it changes rapidly, from tide to tide, storm to storm and season to season, and it faces extreme events such as storms, storm surges, tsunami and cyclones (Getting Started Guide).

Ways to classify coasts

Coasts can be classified in several ways (spec 2.3.1):

• Geology: rocky coasts of resistant rock (granite, many limestones) or less resistant rock (clays, glacial till).
• Energy level: high-energy coasts face strong, frequent, large waves with a long fetch (often erosional, cliffed); low-energy coasts have small waves (sheltered bays, estuaries, often depositional: salt marshes, mudflats).
• Sea-level change: emergent coasts where land rose relative to the sea (raised beaches) and submergent coasts where the sea rose relative to the land (rias, fjords).
• Relief: cliffed coasts versus low-lying coastal plains.
• Sediment: alluvial coasts built of river sediment, sandy coasts, shingle coasts.

The Getting Started Guide also mentions tidal range: microtidal, mesotidal and macrotidal coasts (small to large tidal range).

Primary and secondary coasts

A further classification: primary coasts are shaped mainly by land processes (river deposition building a delta, a drowned valley), while secondary coasts are shaped mainly by marine processes (wave erosion of cliffs, a spit built by longshore drift). Most coasts show both, so a classification is a simplification; examiners reward using more than one basis when you describe a coastline in a resource.

Worked example

A photograph shows tall cliffs of hard rock facing the open ocean, with large waves and no beach. Classify the coast in three ways.

1. Geology: resistant rock (cliffs stand tall, no beach of eroded material).
2. Energy: high energy (large waves, open ocean, long fetch).
3. Relief: cliffed coast.

Answer: A resistant, high-energy, cliffed (rocky) coast.

Check yourself

1. Which part of the littoral zone is only reached by waves during storms?
   • Foreshore
   • Nearshore
   • Backshore
   • Offshore
   Show answer

   Backshore. The backshore lies beyond normal high tide, so only storm waves reach it.

2. A sheltered estuary with small waves and wide mudflats is best described as
   • a low-energy coast
   • a high-energy coast
   • an emergent coast
   • a cliffed coast
   Show answer

   a low-energy coast. Small waves and deposition of mud indicate low energy.

3. A coast where the sea has risen relative to the land, drowning river valleys, is
   • emergent
   • concordant
   • submergent
   • high energy
   Show answer

   submergent. Submergent coasts are drowned by relative sea-level rise; rias are an example.

4. A delta built mainly by river deposition is an example of a
   • secondary coast
   • primary coast
   • discordant coast
   • backshore
   Show answer

   primary coast. Primary coasts are shaped mainly by land-based processes such as river deposition.

5. Why is the littoral zone described as dynamic?
   • It never changes in shape
   • It only exists on cliffed coasts
   • It is unaffected by people
   • It changes rapidly with tides, storms and seasons
   Show answer

   It changes rapidly with tides, storms and seasons. Sediment, beach profiles and landforms change over hours to decades.

6. Explain why a coast made of glacial till facing a long fetch would be classified as high energy and less resistant.
   Show answer

   A long fetch lets winds build large, powerful waves, so wave energy is high; glacial till is soft unconsolidated material, so it is easily eroded and is less resistant.. Fetch gives energy; soft material gives low resistance.

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Sources

• Pearson Edexcel International Advanced Subsidiary/Advanced Level in Geography specification, Issue 3 (September 2025)
• Pearson IAL Geography Getting Started Guide

Last updated 8 November 2026. Spotted a mistake? Tell us.