Coasts Notes

Question 1

What is a sediment cell

Answer 1

A stretch of coastline usually bordered by two prominent headlands where the movement of sediment is mostly contained

Question 2

Where is offshore

Answer 2

Area beyond the point where waves impact the seabed and only deposition occurs

Question 3

What comes after offshore

Answer 3

Nearshore

Question 4

What is nearshore

Answer 4

Zone of shallow water close to shore from deeper offshore waters to the low tide line

Question 5

What comes after nearshore

Answer 5

Foreshore

Question 6

What is the foreshore

Answer 6

Part of the shore that lies between the high tide and low tide line, covered and uncovered by the tide and known also as the intertidal zone

Question 7

What is the backshore

Answer 7

Area of beach lying above the high tide line, usually only affected by v. High tides and storms
Can contain dunes and berms

Question 8

What is the shore

Answer 8

The narrow strip of land that lies between the lower water line and the permanent vegetation or cliffs, includes foreshore and backshore

Question 9

What is a marine terrace

Answer 9

A flat, step-like platform along a coast formed by the uplift of land or a drop in sea level, representing a former shoreline

Question 10

What is a berm

Answer 10

Ridges of sand or gravel deposited by wave action on the backshore of a beach; shows they limit of wave run-up and can form multiple ridges during periods of high tides or storms

Question 11

What is a breaker

Answer 11

Waves that become too steep to support themselves so they break and collapse as they approach shallow water near a coast
Responsible for most erosion and sediment movement on a beach (energy input)

Question 12

What is a coastal area

Answer 12

A broad zone where land meets hte sea including coastal planes, beaches, dunes,, estuaries and wetlands
Can extend inland as far as there is marine influence

Question 13

What is a coast

Answer 13

The general area where land meets the sea including hte shore and adjacent land and sea influenced by coastal processes of waves, tides and sediment movement.

Question 14

What is wave run-up

Answer 14

The maximum vertical distance that a wave reaches as it travels up the shore after breaking, its how far the water from a wave goes up the beach face

Question 15

What happened during the Quaternary glacial and interglacial periods

Answer 15

Sea levels rose and fell several tides in response to the global water cycle

Question 16

What is isostatic uplift/(rebound)

Answer 16

Rise of land caused by the weight of ice pressing down on a piece of land is removed

Question 17

When was storm Eunice

Answer 17

February 2022

Question 18

What happened in storm Eunice

Answer 18

Large storm surge
Coastal flooding
High winds > big destructive waves

Question 19

What caused storm Eunice

Answer 19

Low pressure

Question 20

What happened to the cliff and beach profile in storm Eunice

Answer 20

Cliffs collapsed
Chalk and limestone cliffs weathered and eroded (carbon transfer)
Beach profile altered

Question 21

What is the main driver of waves

Answer 21

The wind

Question 22

Definition of wind

Answer 22

The movement of air from one place to another

Question 23

What causes wind

Answer 23

Air moves from high pressure to low pressure
The greater the pressure gradient, the faster the wind travels

Question 24

Why does the UK get a prevailing wind

Answer 24

The UK gets prevailing westerlies from across the Atlantic

Question 25

What is fetch

Answer 25

Distance of open water that the wind blow

Question 26

What are the 3 factors that affect size and strength of waves

Answer 26

Fetch Duration of wind Strength of wind

Question 27

How does duration of wind affect wave size

Answer 27

Longer the wind blows, the more energy is transferred

Question 28

How does strength of wind affect wave size

Answer 28

Higher Pressure gradient means energy is transferred faster

Question 29

What is a tidal current

Answer 29

A current strongest near the shore and estuaries along the coast due to the tide

Question 30

How does wind drive currents?

Answer 30

It drives localised currents and can result in coastal upwelling It drives surface currents in the open ocean and circulates water in ocean basins

Question 31

What is thermohaline circulation

Answer 31

Movement of water due to heat and salinity of water that affects density

Question 32

What is coastal upwelling

Answer 32

Oceanographic process where cold water rises to surface at coasts due to winds blowing parallel to the coast pushing warm waters away

Question 33

What is the ocean conveyor belt

Answer 33

Combination of currents where 4/5 oceans transfer water

Question 34

How does temperature affect density

Answer 34

Increased temp > lower density > cold sinks and hot rises

Question 35

How does salinity affect density

Answer 35

Increased salt > higher density > sinks below less salty water

Question 36

How long is the Gulf Stream

Answer 36

10,000km

Question 37

How fast does the Gulf Stream move

Answer 37

2m/s

Question 38

How much water does the Gulf Stream Move

Answer 38

100 million m^3 / s to Europe

Question 39

What does the south east trade winds drive

Answer 39

Warm surface water to the Gulf of Mexico

Question 40

What directs the Gulf Stream to Europe

Answer 40

Coriolis effect and wind direction

Question 41

What do scientists worry that will happen to the Gulf Stream

Answer 41

Standstill due to climate change; the urrent wouldn’t be dense enough so would stop

Question 42

How will the gulf stream stopping affect the distribution of heat

Answer 42

Europe would decrease in avg. temperature by 5-10 degrees C

Question 43

What are the 7 sources of sediment

Answer 43

Rivers Cliff erosion Longshore drift Wind Glaciers Offshore Volcanoes

Question 44

How many sediment cells in England and Wales

Answer 44

11

Question 45

What are larger cells divided into

Answer 45

Sub-cells

Question 46

What is a sediment cell

Answer 46

Area of a coastline where movement of sand, sediment and shingle is largely contained

Question 47

What is weathering

Answer 47

Rocks broken down by mechanical and chemical processes in situ caused by weather

Question 48

What is mass-movement

Answer 48

Rocks loosened by weathering move down a slope under the influence of gravity

Question 49

What is frost shattering

Answer 49

Freeze thaw where water goes into cracks, freezes expands then breaks the rocks down

Question 50

What is salt crystallisation

Answer 50

Geomorphic process where soluble salts pour into the fissures of rocks and they crystallise when the water evaporates, putting pressure on the rock, causing it to break down

Question 51

What is wetting and drying

Answer 51

Water enters pores in rock, causing them to expand, water then dries out of the pores causing them to contract This cycle repeats, eventually causing them to break down the rock

Question 52

What is biological weathering

Answer 52

Break down of rock by the action of vegetation and coastal organisms in situ

Question 53

2 Example of biological weathering

Answer 53

The Piddock, a shellfish, drills into rock Seaweed attaches itself to rock, causing it to pry away loose rocks

Question 54

What is chemical weathering

Answer 54

Rock exposed to air and moisture leads to chemical processes that break down the rock in situ