Coastal Landscape Development

Question 1

Define spit

Answer 1

A long, narrow ridge of land that joins to the mainland at one end and projects out into the sea / across a river estuary.
Usually on a drift-aligned coast.

Question 2

Which types of coastline do spits usually form at?

Answer 2

Drift-aligned coast

Question 3

Describe the formation of a spit

Answer 3

LSD carries material along coast -> build up of material in more sheltered water (behind headland) -> storms build up more material above HWM (permanent) -> length of ridge (spit) extends -> wave refraction / 2nd most dominant wind curves end of spit towards mainland

Question 4

What feature may form behind a spit?

Answer 4

Salt marsh

Question 5

What factors affect the formation of a spit?

Answer 5

Longshore drift - wave energy, fetch.
Prevailing winds.
River current.

Question 6

Name the types of spits

Answer 6

Simple

Compound

Question 7

Describe the features of a simple spit

Answer 7

Can be straight or recurved.

DO NOT have minor spits / recurved edges along their landward edge.

Question 8

Describe the features of a compound spit

Answer 8

Can be straight or recurved.
DOES have minor spits / recurved edges along their landward side -> possibly marking the position where they terminated in the past

Question 9

What might the minor spits / recurved edges on a compound spit show?

Answer 9

May mark the position where the spit terminated in the past

Question 10

Define tombolo

Answer 10

A spit that joins an island to the mainland

Question 11

Give examples of where spits are found

Answer 11

Spurn Head, East Yorkshire

Sandy Hook Spit, New Jersey, USA

Question 12

Give examples of where tombolos are found

Answer 12

Chesil Beach, UK

The Angel Road of Shodo Island, Japan

Question 13

Give the factors that affect the formation of tombolos

Answer 13

Longshore drift
Prevailing winds
Distance from mainland to island

Question 14

Define offshore bar

Answer 14

Where a ridge of beach material that remains semi-submerged accumulates seaward of the breaker zone

Question 15

Define bar

Answer 15

When a spit grows across a bay and joins two headlands

Question 16

What feature forms behind a bar

Answer 16

Lagoon (former bay)

Question 17

How did some bars form after the last ice age?

Answer 17

The result of onshore migration of material from offshore, as sea levels rose after last ice age

Question 18

By how much can bars be submerged by incoming tides?

Answer 18

Partially / completely submerged

Question 19

Give examples of where bars are found

Answer 19

Slapton Ley, Devon
Chesil Beach - formed by combination of onshore migration + LSD.
Arabat Spit, Sea of Azov - longest spit in the world, joins towns in Ukrain to Crimea.

Question 20

Give the factors affecting the formation of bars

Answer 20

LSD - wave energy, fetch
Prevailing wind
Distance from headland to headland

Question 21

How has sea level changed over the past 10,000 years?

Answer 21

Sea level has generally been rising over the past 20,00 years.

Sea level appears to be lowering in Scotland (northwest), due to isostatic uplift of land.

Question 22

Name the coastal features that form due to rising sea level

Answer 22

Dalmatian coast
Fjords
Rias
Estuaries
Shingle beaches

Question 23

What is a fjord? Give an example

Answer 23

Drowned glacial valley.

Eg Sogne fjord, Norway

Question 24

What is a ria? Give an example

Answer 24

Drowned river valley.

Eg River Dart, Devon

Question 25

What is an estuary? Give an example

Answer 25

Drowned, shallow, lowland river valleys. Eg Humber estuary

Question 26

How do shingle beaches form?

Answer 26

Where sediments previously deposited on the contents shelf were above sea level. Rising sea levels have swept up the sediment and deposited it on present day coasts.

Question 27

Name the coastal features that form due to falling sea level

Answer 27

Raised beaches / relict cliffs | Marine platform

Question 28

What is a raised beach / relict cliff? Give an example

Answer 28

Beaches and cliff lines elevated above sea level and exposed following deglaciation -> land height rises. Eg Isle of Arran, Scotland

Question 29

What is a marine platform? How does it form?

Answer 29

Where an expanse of gently sloping, formerly submerged land has been exposed by uplift of land / lowering sea level

Question 30

What is a Dalmatian coastline? How do they form? Give an example

Answer 30

Form where valleys (esp glacial valleys) lie parallel to each other. Valleys are flooded by sea level rise -> tops of valleys remain above sea surface -> appear to be islands that run parallel to the coast.

Question 31

Give the potential impacts of sea level change on coasts

Answer 31

* Increased coastal flooding -> esp during spring tides / strong winds. * More erosion -> waves attack areas previously above high tide. * Receding coastlines. * Zone where seawater mixes with fresh water in rivers may reach further inland. * Increased flooding of areas away from coastline -> river flooding. * More frequent / intense extreme sea level events eg storm surges. * Increased erosion to dunes, salt marshes, mudflats. * Increased investment in coastal protection for areas of high economic value.

Question 32

What percentage of the population of England / Wales live within 10km of the coast?

Answer 32

30%

Question 33

There is a high proportion of what types of infrastructure in coastal regions?

Answer 33

Agricultural land. Manufacturing industry. Energy supply. Transport links.

Question 34

What is the worth of the infrastructure / resources that are at risk from coastal flooding? Coastal erosion?

Answer 34

£120 billion - flooding. | £10 billion - erosion.

Question 35

What is the current rate of sea level rise?

Answer 35

3mm per year

Question 36

Sea level rise between 1961-2003 was caused by what?

Answer 36

40% Thermal expansion of water. | 60% melting glaciers, ice caps, ice sheets.

Question 37

What are the main causes of sea level rise? How / by how much?

Answer 37

* Ocean expansion - SLR of 0.5-1.6mm per year. * Mountain glaciers - glaciers melt faster than they gain mass through snowfall -> enough water in glaciers to raise sea levels by 50cm. * Ice-sheets - Greenland alone is covered by enough ice to raise sea levels by over 7 metres.