Geography Terms - Coasts

Front 1

Fairly weak backwash
Strong backwash
They erode and transport material away from beaches

Back 1

Destructive Waves

Front 2

Strong Swash
Weak backwash
Because swash is stronger than the backwash they tend to deposit material and build up beaches.

Back 2

Constructive Waves

Front 3

The waves breaking and traveling up the beach carrying load. Waves will break and the swash will travel in the direction of the wind.

Back 3

Swash

Front 4

The waves returning to the sea with load. Waves will take the shortest possible route back to the sea (gravity).

Back 4

Backwash

Front 5

What components make up a Destructive Wave?

Back 5

Destructive waves are created in storm conditions
They are created from big, strong waves when the wind is powerful and has been blowing for a long time.
They occur when wave energy is high and the wave has travelled over a long fetch.
They tend to erode the coast.
They have a stronger backwash than swash.
They have a short length and are high and steep.

Front 6

What components make up a Constructive Wave?

Back 6

They are created in calm weather and are less powerful than destructive waves.
They break on he shore and deposit material, building up beaches.
They have a long wavelength, and are low in height.
They have less of a backwash than destructive waves.

Front 7

This is when sea water and air get trapped in cracks. The increasing pressure of the water and air cause the rocks to crack.

Back 7

Hydraulic Pressure

Front 8

Rocks been thrown into the cliffs by waves and breaking off bits of the cliff.

Back 8

Corrasion (Abrasion)

Front 9

The slight acidity of sea water causing bits of the cliff to dissolve.

Back 9

Corrosion (Solution)

Front 10

Rocks, sand and stones being thrown into each other by the sea current and waves.

Back 10

Attrition

Front 11

This is the process of waves moving (transporting) material (load) along a coastline.

Back 11

Longshore Drift

Front 12

Conditions needed for Coral reefs

Back 12

Tropical sea conditions (between the two tropics)
Warm waters (must be over 18 degrees centigrade year round)
Clear water ( no sediment)
No pollution
Sunlight
Water less than 60 metres deep
No strong currents

Front 13

Fringing Reef

Back 13

Fringing reefs circle or fringe the coastline or islands. They are often protected by barrier reefs further out to sea, so the plants and animals that live in fringing reefs are suited to low wave energy environments.

Front 14

Barrier Reef

Back 14

These occur further from the sea and are commonly separated from the mainland or island by a deep lagoon. Barrier reefs are normally older and wider than fringing reefs. The Great Barrier reef in Eastern Australia is a barrier reef and stretches for 1600km.

Front 15

Atoll

Back 15

a ring-shaped reef, island, or chain of islands formed of coral. It is formed after the island sinks

Front 16

a steep rock face, esp. at the edge of the sea. They are formed by a combination of erosion and weathering, weathering working on the upper parts of the cliff and erosion wearing away the base of the cliff.

Back 16

Cliff

Front 17

At high tide the power of the sea attacks and erodes the bottom of the cliff. Over time this erosion creates a wave cut notch (basically an eroded hole at the bottom of the cliff). As the wave cut notch gets bigger, the weight of rock above the notch gets greater. Eventually the cliff can not support its own weight and it collapses.

Back 17

Wave cut platform

Front 18

Cave

Back 18

The waves always look for weaknesses in the headland (cracks and joints). If they find a crack or a joint they will start attacking it. Hydraulic pressure will be the main type of erosion. Overtime the crack may turn into a cave.

Front 19

Arch

Back 19

The waves always look for weaknesses in the headland (cracks and joints). If they find a crack or a joint they will start attacking it. Hydraulic pressure will be the main type of erosion. Overtime the crack may turn into a cave. Slowly the cave will get bigger and cut all the way through the headland, making an arch.

Front 20

Stack

Back 20

As the arch gets bigger the weight of the arch roof gets too great and it collapses, leaving a stack.

Front 21

Stump

Back 21

The stack is then eroded by the sea and weathered from the air leaving a stump.

Front 22

An indented area of land normally found between two headlands. They are usually more sheltered so there is less erosive power, meaning you often find beaches in bays.

Back 22

Bay

Front 23

A piece of land that sticks out into the sea. Waves refract around them so they experience a lot of erosion forming features like arches and stacks.

Back 23

Headland

Front 24

This is the accumulation of sand between the lowest spring tides and the highest spring tides. They can be made out of sand, shingle and/or pebbles. They receive their material from longshore drift, constructive waves, cliff erosion and river discharge.

Back 24

Beaches

Front 25

Depositional Landforms

Back 25

Tombolos
Spits
Bars

Front 26

It is a long thin stretch of sand connected to the mainland but stretching out into the sea. They are formed in areas of calmer water where the sea has less energy. Found at the mouth of a river.

Back 26

Spits

Front 27

A spit that connects two headlands or runs across the face of a small cove

Back 27

Bar

Front 28

They are very dynamic, which means they are constantly changing. They are found behind berms and are basically an extension of the beach. They are formed by dry sand being blown up the beach.

Back 28

Sand Dunes

Front 29

A low energy, intertidal ecosystem that develops behind a spit. It will have some salt resistant vegetation.

Back 29

Salt marsh

Front 30

a small, isolated platform of coral.

Back 30

Patch Reef

Front 31

Offshore

Back 31

Offshore is the area below the normal low tide.

Front 32

Foreshore

Back 32

The foreshore is the area in between normal high and low tide

Front 33

Back-shore

Back 33

The backshore is the area above the normal high tide level.