IGCSE GEOGRAPHY 2.1

Land and the three types of weathering

-Chemical -Physical -Biological Hard or soft rock Cliff will differ to a sand dune

Human Activity

Water pollution

Fetch

Wave formation. Winds that creates wave direction

Swash

When a wave breaks it deposits the water is washed up into the beach. This is called the swash. Then the water runs back down the beach, which is called the backwash. With a constructive wave, the swash is stronger than the backwash. With a destructive wave, the backwash is stronger than the swash.

Abrasion

When rocks, pebbles scrape against the chiefs

Hydraulic Action

air is trapped in the cracks forcing them to open

The Coastal environment consists of 2 parts

onshore up to 60km inland and offshore up to 370km out to sea.

The coast

The coastline l is where the cost is the transition zone between the land and sea

Tombolos

The tombolos are spits that continue to grow seawards until they have reached/joined the island. They are formed by connecting a spit into the mainland coast of the island.

Bars

A bay is formed between two headlines, and develops in a bay. The beach must gently slop in order for the bar to form. There must Not be a river entering the bay as this would insettle the material that was deposited. As the waves come in and meet the gently sloping beach, they will break, or reduce or in speed as there is friction when the waves meet the sea floor. This results in the material being carried by the waves to be deposited - and over time a bar forms. A lagoon can form behind the bar.

Halophyte

A halophyte is a salt-tolerant plant that grows in soil or waters of high salinity, coming into contact with saline water through its roots or by salt spray, such as in saline semi-deserts, mangrove swamps, marshes and sloughs and seashores.

Constructive waves

A low wave that deposits material after it breaks, building up the beach. Swash is stronger than backwash.

What is created through longshore drift

Bars Cuspate fforelands Tombolos Sand dunes

Corrasion

Chemicals in the water dissolve rocks.

CUSPATE FORELANDS

Cuspate forelands are triangular-shaped accumulations of sand and shingle that extend seawards. It seems likely that many of them develop as a result of longshore drift occurring from two different directions; the head-on collision of the two drifts lead to the deposition of sediment and so to the formation of the foreland. The head on collision of both longshore leads to material being deposited and the formation of the foreland

Weather and climate

Effect the waves Change infrastructure/zoning areas Less/more flooding

How do sand dunes form?

Embryo Dune - Sand Fore Dune - Small grass Yellow Dune - More grass Grey Dune - More grass, small plant Dune Slack - Little water small life example small plant Mature Dune - Trees

Sea

Erosion or depression More erosion loss of ecosystem for example animals, plants, humans

Fetch

Fetch length, along with the wind speed wind speed, determines the size of the waves produced. The wind direction is considered constant. The longer the fetch and the faster the wind speed, the more wind energy is imparted to the water surface and the larger the resulting sea state will be. The more friction it creates a bigger wave.

Groynes

Management (hard) engineering. Protects the coastline from erosion.

Destructive waves

Opposite to Constructive waves, large waves that carry sand and other material away in the backwash creating erosion.

attrition

Rocks being carried by the river smash together and break into smaller, smoother and rounder particles.

Cave, stack stump (erosional landform)

See picture

Describe and explain the process of longshore drift and the landforms that it creates.

Task 1 Hydraulic action - this is the sheer power of the waves as they smash against the cliff. Air becomes trapped in the cracks in the rock and causes the rock to break apart. Abrasion - this is when pebbles grind along a rock platform, much like sandpaper. Over time the rock becomes smooth. Attrition - this is when rocks that the sea is carrying knock against each other. They break apart to become smaller and more rounded. Solution - this is when sea water dissolves certain types of rocks. In the UK, chalk and limestone cliffs are prone to this type of erosion. Task 2 1. On most beaches longshore drift is in one direction and a zigzag motion. 2. With brief changes in the wind direction there are changes in the wave direction. 3. This can cause material to be transported in the opposite direction along the beach. 4. Longshore drift is the link between erosion and deposition. 5. Material is eroded and transported further along the beach. Depositional landforms are produced where mud, sand and shingle accumulate faster than they can be moved away from by the waves. This normally occurs along coastlines dominated by constructive waves (where the swash is stronger than the backwash) TASK 3 - Spits are long narrow beaches of sand and shingle that are attached to the land at one end. They extend across a bay or where the coastline changes direction. They are formed by longshore drift in one direction. At the end of the beach, the material being transported is deposited, and salt marshes may form. The waves and wind may change direction which curves the spit.