Coasts Landforms

Question 1

Formation of caves, arches stacks and stumps

Answer 1

-hydraulic action and abrasion form cracks in the headland to creat small caves
-the rock above may collapse
-marine erosion widens the fault
-falls through marine erosion and sub aerial processes through to other side creating arch
-continues to widen until it can’t support itself and falls through mass movement
-leaves a stack
-marine erosion attacking base will become stump

Question 2

Formation of wave cut notch to a platform

Answer 2

-waves erode cliff through hydraulic action at the high tide line
-this creates a wave cut notch
-notch becomes deeper as subaerial weathering weakens top cliff
-become unstable and falls under its own weight through mass movement
-leaves behind a wave cut platform

Question 3

Depositional landforms

Answer 3

Beach
Spits
Tombolo
Barrier beach
Offshore bar

Question 4

Formation of beach

Answer 4

Accretion of sediment during constructive waves in summer months
Dependent on angle of prevailing wind in relation to the land

Question 5

Swash aligned beaches

Answer 5

Wave approaches perpendicular to coast so limits longshore drift
Wave refraction may reduce speed of high energy waves

Question 6

Drift aligned beaches

Answer 6

Waves approach at an angle so LSD moves sediment far along the beach
May lead to formation of a spit

Question 7

Formation of spit

Answer 7

When long shore drift causes beach to extend out to sea by a change in direction of the coastline
Can create salt marsh in its sheltered environment
Length depends on amount of rivers
Change in wind direction will curve the spit

Question 8

Formation of barrier beach

Answer 8

When a beach or spit extends across a bat to join two headlands
Traps water behind makes a lagoon
May form due to rising sea levels after last glacial period
If becomes separated it will become a barrier island

Question 9

Formation of offshore bars

Answer 9

An offshore region where sand is deposited when waves lose energy to carry sediment to the shore
May form when wave breaks early
Waves may pick this up (input to coastal zone)
May absorb wave energy

Question 10

Landforms erosion

Answer 10

Caves arches stacks stumps
Headlands and bays
Wave cut notches and platforms

Question 11

2 types of physical weathering

Answer 11

Freeze thaw
Sly crystallisation

Question 12

2 types of chemical weathering

Answer 12

Oxidation
Carbonation

Question 13

2 types of biological weathering

Answer 13

Plant roots
Decaying vegetation

Question 14

Explain carbonation

Answer 14

Rainwater absorbs CO2 from atmosphere
Creates weak carbonic. Acids
Reacts with calcium carbonate in rocks
Forms calcium bicarbonate
Easily dissolves

Question 15

Explain oxidation

Answer 15

Minerals exposed to air through cracks in rock
Oxidised and increase in volume
Esters pressure on rock and it crumbles

Question 16

6 factors mass movement is dependent on

Answer 16

Weathering
Ground saturation
Vegetation
Cliff angle
Rock type
Rock structure

Question 17

Define deposition

Answer 17

Deposition occurs when the sediment becomes too heavy for the wave to carry or the wave loses energy

Question 18

Define erosion

Answer 18

Erosion involved the removal of sediment from a coastline

Question 19

Types of erosion

Answer 19

Corrosion
Abrasion
Attrition
Hydraulic action
Wave quarrying

Question 20

Factors effecting erosion

Answer 20

Waves
Beaches
Subaerial processes
Rock type/lithology

Question 21

4 process of transportation and deposition

Answer 21

Traction
Saltation
Suspension
Solution

Question 22

Explain long shore drift

Answer 22

Waves hit the beach at an angle determined by direction of prevailing wind
Pushes sediment up beach (swash)
Gravity waves carry sediment back down the beach (backwash)

Question 23

Flocculation

Answer 23

(Important in salt and tidal marshes)
Clay particles clump together due to chemical attraction and sink due to their high density

Question 24

What promotors steep cliff development

Answer 24

Absence of a beach
Long fetch
High wave energy
Sedimentary rocks vertical strata

Question 25

What promotes gentle cliffs

Answer 25

Low energy waves
Short fetch
Water rock

Question 26

Inputs of sand dunes

Answer 26

Supply of sand
Onshore winds
Large tidal range

Question 27

sand dune succession

Answer 27

Sand blown by onshore winds and trapped behind obstacle e.g driftwood
Embryo dunes are colonised by pioneer species
Long roots of marram grass help bind the ground together
Foredunes occur and become fixed forming an organic layer

Question 28

Development of mudflats

Answer 28

Develop in sheltered shorelines and low energy coasts
Composed of silt and clay at the bottom of estuaries submerged by high tide
Saltwater flows and river freshwater flows meet
Causes flocculations where the individual particles aggregate together

Question 29

Development of salt marshes from mudflats

Answer 29

Low lying vegetation like eelgrass begins to grow in mudflats
Slows currents and leads to more deposition
Pioneers begin to colonise known as halophytes - tolerant to salty conditions
E.g glasswort and spartina
Prisoners develop amc become closer, slow down currents and trap sediments