Landscapes & Features of The Littoral Zone

Landscapes & Features of The Littoral Zone

What is the littoral zone?

The coastal area affected by wave action, divided into backshore, foreshore, nearshore, and offshore zones.

How is the coast a system?

It’s an open system with inputs, stores, transfers, and outputs; it strives for dynamic equilibrium.

What is positive feedback

A process that increases or amplifies the original change in the system, leading to a greater effect.

What is negative feedback

A process that reduces or counteracts the original change, helping to stabilise the system

What are concordant and discordant coastlines?

Concordant: rock layers parallel to coast;

Discordant: rock layers at right angles to coast.

What are high-energy coasts?

Areas with destructive waves, strong winds, high erosion, and rocky landscapes.

What are low-energy coasts?

Sheltered areas with constructive waves, high deposition, and features like beaches and salt marshes.

What influences coastal morphology?

Rock type and structure

• strata: layers of rocks

• faults: Breaks or fractures in rock where there has been movement due to stress.

• folds,

• bedding planes: Horizontal cracks

• dip

• joints: vertical cracks

Example of concordant coastline?

Lulworth Cove, Dorset – resistant Portland Limestone in front of weaker rocks.

What is a Dalmatian coast?

flooded concordant coastline where anticlines become islands (e.g., Croatia).

What is coastal recession?

The retreat of the coastline inland due to erosion, sea level rise, or submergence.

What is differential erosion?

Varying erosion rates due to rock resistance, leading to features like headlands and bays.

How does vegetation stabilise coastlines?

Roots bind sediment, reduce wind speed, and increase deposition and soil formation.

What are pioneer species?

First plants to colonise harsh coastal environments (e.g., marram grass, lyme grass).

What is wave refraction?

Wave refraction changes the amount of energy reaching the shore on a small local scale

How are sand Dunes formed?

• Windblown sand is deposited against an obstruction: Pebbles or driftwood

• As more sand particles are caught, the dunes grow in size, forming rows aright angles to the prevailing wind

• Overtime, the ridges of the dunes will be colonized and xed by vegetation in a process called succession

what does Pioneer species have to deal with?

• Salinity Lack of moisture as sand drains quickly (highly permeable)

• Wind

• Temporary submergence by wind-blown sand

• Rising sea levels

The types of dunes are

• Embryo dunes

• Fore dunes

• Yellow dunes

• Grey dunes

• Mature dunes

Where do salt marshes form?

Estuarine areas with sediment from rivers and shelter from waves.

What is flocculation?

When clay particles stick together due to saltwater and settle, forming new land.

What is the role of cord grass?

Colonises raised sediments, stabilising marshes and allowing further succession.