General

Question 1

How is the coast a system?

Answer 1

Has Inputs - energy from waves wind tides and sea currents
Stores - erosional and depositional landforms and landscapes
Flows - erosional processes, wind, water, transportation
Outputs - dissipation of wave energy, accumulation of sediment above the tidal limit, sediment moved beyond local sediment cells

Question 2

How do waves break?

Answer 2

Wave enters shallow water -> friction with seabed increases -> wave slows as it drags along the bottom -> wavelength decreases and waves start to bunch up -> waves increases in height -> wave plunges or breaks on the shore line

Question 3

what are the 3 Types of breaking waves?

Answer 3

Spilling - steep waves on gently sloping beaches
Plunging - steep waves on steep beaches
Surging - low angle waves on steep beaches

(know diagrams)

Question 4

What are the two types of waves

Answer 4

Constructive - low, long length, low frequency, gentle spill onto shore, weak backwash, low sediment movement, Swash > backwash
Destructive - high, steep, high frequency, powerful backwash and sediment movement, swash < backwash

Question 5

What is Wave Refraction?

Answer 5

Process by which waves break onto an irregularly shaped coastline - e.g. a headland separated by two bays.

Wave drags in the shallow water approaching a headland -> wave becomes high, steep and short -> the part of wave in deep water moves faster -> the wave bends -> the low energy waves spills into the bays as most of the energy concentrates on the headland

Question 6

Two Tidal Cycles

Answer 6

Spring tide - highest tides occur when the moon and sun are aligned so strong gravitational pull
Neap tides - moon and sun are at angles so gravitational pull is weak

Question 7

Difference between Lithology and Structure

Answer 7

Lithology is the chemical and physical structure of rocks - weak rocks such as class will erode faster than hard rocks like basalt
Structure is features of jointing, faulting and bedding planes alongside their permeability

Question 8

3 types of ocean currents

Answer 8

Longshore currents - most waves approach the shoreline at an angle. this creates a current of water running parallel to the shoreline
Rip Currents - strong currents moving away from the shoreline as a result of build-up of seawater and energy along the coastline
Upwelling - Cold water moves to surface, displacing the warmer water.

Question 9

4 types of mechanical weathering

Answer 9

Freeze thaw - water enters cracks, expands, freezes, exerts pressure
Pressure release - overlying rocks removed by weathering, rocks below expand, fracture
Thermal Expansion - rocks expand when heated and shrink when cooled, when frequent fractures and flakes
Salt Crystallisation - Salt water seeps into pores, evaporates, salt expands - Sodium sulphate up to 300%

Question 10

5 types of chemical weathering

Answer 10

Oxidation - minerals (iron) react with oxygen in air / water
Carbonation - stalactites formed by rain water + CO2, forming carbonic acid, reacting with calcium carbonate in rocks like limestone
Solution - some salts are soluble in water
Hydrolysis - reaction between rock minerals and water (silicates +water = clay)
Hydration - water molecules + rock create bigger and larger molecules.

Question 11

Types of Biological weathering

Answer 11

Tree Roots and Burrowing animals - grow/ bury into cracks exerting outwards pressure
Organic Acids - produced by decomposition of plants and animals, causes soil water to be more acidic and react with some minerals.

Question 12

5 types of mass movement

Answer 12

Land slides - cliffs made of soft rock slip when wet
Rockfalls - rocks undercut by the sea leading to falling rocks
Mud flows - Heavy rain causes fine material to move downhill
Slumping - where soft material overlies resistant material
Soil Creep - very slow movement of soil particles down slope

Question 13

5 types of wave erosion

Answer 13

Hydraulic action - force of water on rocks
Pounding - Wave crashes into rock, air trapped in cracks, as wave releases air is released, weakens rock over time
Abrasion - sand, shingle and boulders picked up by sea
Attrition - wearing down of pebbles as they rub
Solution - when sea water erodes certain rocks

Question 14

4 types of transportation

Answer 14

Traction - large boulders
Saltation - small stones
Suspension - very small particles
Solution - dissolved particles

Question 15

Explain the process of longshore drift

Answer 15

Wave approaches shore in direction of prevailing winds, swash moves material up the beach in direction of the wave, backwash moves the material back down the steepest gradient, usually perpendicular to the swash

Question 16

Explain the formation of a headland and a bay

Answer 16

Headlands and bays result from discordant coastlines.
The areas of soft rock are more easily and quickly eroded whereas the harder rock is more resistant to processes of weathering and erosion.
Where harder rock is present, headlands occur and where softer rock is being eroded, bays are formed.
The processes of erosion that take part in this can be hydraulic action, attrition and different types of weathering.
Constant attacking of the waves and material from the sea on the cliff face causes erosion of soft rock, leaving bits of land ‘jutting out’.

Question 17

Explain the formation of a cliff and then a wave cut platform

Answer 17

1) high waves concentrate erosion at the base of a cliff, the cliff is undercut, forming a wave - cut notch, over time the undercut cliff collapses and the cliff face retreats, a gently sloping forefront to the cliff is left - a wave cut platform, the wave cut platform is cut into by abrasion and also eroded by hydraulic action, over time waves break further out to sea, therefore energy dissipates

Question 18

Explain the formation of a geo and a blow hole

Answer 18

A geo is a steep sided inlet formed on a coastline where there is a weakness (joint or fault) in the rock which is exposed to erosion. when a geo becomes enlarged and by erosion and the roof collapses, it becomes a blow hole (google pictures)

Question 19

Formation of a cave, arch, stack, stump

Answer 19

…

Question 20

Formation of a spit / tombolo / bar

Answer 20

Longshore drift carries sediment W -> E, when the coastline changes shape, material will begin to be deposited, the spit develops a hook when there is a secondary wind or a change in direction of the wind, Waves cannot get past a spit, which creates a sheltered area where silt is deposited and mud flats or salt marshes form.
A spit that joins an island to the mainland is a tombolo
A spit going over a bay is a bar.

Question 21

Explain how a beach is formed and the characteristics

Answer 21

beaches are an accumulation of material coming from these sources: 5% cliff erosion, 5% offshore, 90% from rivers. draw a diagram with 8 features

Question 22

Formation of a salt marsh

Answer 22

A salt marsh begins when mud and silt are deposited along a sheltered part of the coastline. This is because rates of deposition are greater than transportation due to the lack of energy in the waves. Often salt marsh is found on the inside of a spit.
The deposition builds up over time meaning that the mud breaks the surface to form mudflats. Some plants then begin to grow. The first plant is typically Cordgrass. These plants are called pioneer plants. It is tolerant to seawater and its long roots help hold the mud and sediment together.
Due to the sediment and material accumulating, it gets covered by the tide less. This and rain will leach (wash out) some of the salt. As the salt is now lower in concentration, it means more plants can start to grow in the more fertile soil.

Question 23

What is the difference between eustatic and isostatic change in sea level

Answer 23

Eustatic change - a global change in the volume of sea water e.g. caused by global warming
Isostatic change is a local change in sea level resulting from land falling or rising relative to the sea e.g. tectonic movements

Question 24

How does cooling climate lead to emergent landscapes, how does this then impact landforms

Answer 24

Fall in temperature -> more precipitation as snow -> snow turns to ice -> more water stored on land as ice rather than liquid water in the oceans

as they are now exposed and above the waterline, they are now vulnerable to mass movement and weathering. if sea level rises in the future, they will be vexposed to wave processes again.

Question 25

How does warming climate lead to submergent landscapes, how does this then impact landforms

Answer 25

rise in global temperatures -> melting of ice stores-> increase in the volume of water -> sea level rise
A 1C rise in temp can lead to 2m increase in sea level

Question 26

Explain the formation of a shingle beach

Answer 26

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Question 27

Explain the formation of a ria

Answer 27

Submerged river valley.
eustatic or isostatic
they typically have gently sloping sides,
increased water depth in rias is likely to be
associated with larger waves and greater wave
energy, thereby increasing rates of erosion and
further modification.

Question 28

Explain the formation of a fjord

Answer 28

Submerged glacial valley
Either eustatic or isostatic
very steep, not overly wide. due to the nature of glacial erosion
shallow threshold at the opening
Scree and morraine at the shores - sediment from glacial time

Question 29

Explain the formation of a raised beach, abandoned cliff and marine terraces

Answer 29

emergent landform
isostatic or eustatic
Previously, sediment was deposited on the beach and or was vulnerable to erosion - abrasion and hydraulic action
Now vulnerable to weathering