Coastal landforms

Question 1

What is strata

Answer 1

Layers of rock

Question 2

What are bedding planes

Answer 2

Horizontal, natural breaks in the strata, caused by gaps in time during periods of rock formation.

Question 3

What are joints

Answer 3

Vertical fractures

Question 4

What is the dip

Answer 4

Angle at which rock strata lie

Question 5

Formation of a WCP

Answer 5

When Waves concentrate erosion at small area of rock, this leads to cliff becoming undercut. Forming wave cut notch, increasing shear stress of on cliff. Cliff retreats leaving WCP. Example of negative feedback.

Question 6

What is differential erosion

Answer 6

Rocks erode at different rates, due to weaker beds and more resistance rocks

Question 7

Flamborough head overview.

Answer 7

Cliff height- 30-100 m
Geology- Chalk, with horizontal bedding planes-resistant
Marin processes- Hydraulic action, solution
Mass movement- Rockfall, 1-2 cm per year
Landforms- WCP, caves, notches

Question 8

Aldbrough overview

Answer 8

Cliff height-5m-10m
Geology- Unconsolidated boulder clay, low shear strength.
Marine processes- Wave quarrying, hydraulic action, cavitation.
Mass movement- Very regular slumping so no caostal landforms -1-2 per year retreat, due to undercutting.

Question 9

How was Selwicks bay created

Answer 9

Tectonic movements folded and faulted the chalk layers, creating cracks. This enlarged the surface area making rock more vulnerable to weathering, erosion and retreat. Creating Selwicks bay.

Question 10

What are Geos

Answer 10

Steep- sided inlet, due to erosion excavating enough material along a fault.

Question 11

What is the building up of a beach called

Answer 11

Accretion

Question 12

What is the storm beach

Answer 12

Ridge of pebbles pushed up by storm waves

Question 13

What are berms

Answer 13

Lower ridges parallel to the storm beach , ridge of material left by HT.

Question 14

What are swash- aligned beaches

Answer 14

Form in low energy environments when waves arrive roughly parallel to the shore.

Question 15

What are drift aligned beaches

Answer 15

Form where the waves approach the coast at an angle. LSD moves the sediment along the beach

Question 16

How are simple spits different to compound spits

Answer 16

Simple spits do not have minor spits or recurred ridges along their landward edge.

Question 17

exmple of spit

Answer 17

Spurn head, Dominant wind direction from NE, creates LSD, sediment moves southwards.
Humber estuary provides change in direction of coastline.

Question 18

When does a bar form

Answer 18

When the sediment from a spit reaches to the other side of the bay.

Question 19

What is an offshore bar

Answer 19

When destructive waves erode sand from the beach with their strong backwash and deposit it offshore. - They absorb wave energy.

Question 20

What is a Tombolo

Answer 20

Where ridges of sand and shingle link the coast to an island.

Question 21

What is Xerophyte

Answer 21

A plant adapted to living in a dry arid habitat like a sand dune.

Question 22

Sand dune development

Answer 22

-Dry sand is transported landwards by onshore winds.
-Wind velocity drops when it encounters an obstacle and sand is deposited
-The sand accumulates to form embryo dunes
Pioneer species colonise
-Sand is anchored, wind flow is further disrupted, deposition continues and sand dune grows into foredunes ort yellow dunes.
-Sand is blown off the top and sand dune slowly migrates landwards.
-A new dune is formed at the strand line.
-Wind weep down the leeward side of the dune and scour the dip until the wet sand is reached and a dune slack is formed.
-Removal of vegetation will result in the sane dune being eroded and forming a blowout.

Question 23

Embryo dune conditions

Answer 23

-Saline environment.
-Windy- sand mobile
-Arid- little freshwater
-PH8, harsh
therefore only specially adapted plants can survive-pioneer species-xerophytic plant.
-

Question 24

Foredune+ yellow dune conditions

Answer 24

Established 50 years ago
-Less saline
-Windy, sand is less mobile
-More minerals due to marram grass decomposed.
-PH7 more acidic due to organic acids from decomposition.

Question 25

Grey dunes conditions

Answer 25

-Rain washed away salt
-Higher organic matter content- decomposed material = acidic ph6
-Cation exchange capacity of soil- displaces minerals and makes available for plant uptake.

Question 26

Formation of a slat marsh

Answer 26

A salt marsh begins when mud and silt are depositied along a sheltered part of coastline, this is because rates of deposition are greater than transportation due to lack of wave energy.
Some plants then colonise the mud flats, called pioneer species. usually eelgrass. It is tolerant to seawater and long roots help hold sediment together. The decomposition builds up over time meaning that the mud breaks the surface to form mudflats, allowing new plants to colonise.
Due to The sediment and material accumulating, it gets covered by the tide even less. The rain will leach some of the salt. As the salt is now lower in concentration, it means more plants can start to grow in more fertile soil.

Question 27

What are mudflats

Answer 27

Develop in estuaries where the sea water flows into the river mouth with each HT and out with each LT.

Question 28

Formation of a mudflat

Answer 28

Where the saltwater flow gently into the estuary it brings large amounts of fine sediments; this meets the equally slow moving river which is also carrying its own sediment.
The meeting of fresh and salt water causes the clay particles to aggregate together, making them heavier and sink. This is known as flocculation.