Coasts

Question 1

What is isostatic change?

Answer 1

A local uplift of land. Result of isostic rebound or tectonic activity.

Question 2

Describe destructive waves.

Answer 2

weak swash and strong backwash
High and steep
Circular cross profile
High frequency- 10-14

Question 3

Describe constructive waves.

Answer 3

Strong swash, weak backwash. Deposits sediment. Long wavelength and low in height.
Elliptical cross profile.

Question 4

What is eustatic change?

Answer 4

A global rise or fall in sea level. Due to global warming.

Question 5

What are sediment cells?

Answer 5

Self contained lengths of coastline- 12 in the UK

Question 6

What determines wave energy?

Answer 6

Fetch
Wind duration
Wind velocity

Question 7

Types of subaerial weathering?

Answer 7

Freeze thaw
Biological
Chemical

Question 8

Mass movement?

Answer 8

Soil creep- less than 40 degrees
Landslide- over 40 degrees
Rockfall

Question 9

What is mass movement?

Answer 9

The movement of material downhill due to gravity

Question 10

Describe longshore drift?

Answer 10

The action of transporting sediment along a coastline.
Swash in direction of prevailing wind.
Backwash at 90 degree angles to the coastline

Question 11

Describe wave cut platform

Answer 11

Erosion at base of cliff
Notch formed
Overhang collapses

Question 12

Describe berms?

Answer 12

Ridges of sand and pebbles found at high tide mark

Formed by deposition by swash

Question 13

Describe runnels

Answer 13

Grooves in sand running parallel to the shore.

Formed by backwash

Question 14

Describe cusps

Answer 14

Crescent shaped indentations on a beach mixed of sand and shingle.
Develop in areas where waves break parallel to the beach and have a large tidal range

Question 15

Describe spring tides?

Answer 15

Sun, moon and earth are aligned. Gives largest tidal range- high tides are at highest and low tides at lowest

Question 16

Describe neap tides?

Answer 16

Earth, moon and sun form a right angle.

Smallest tidal range- low high tides and high low tides.

Question 17

When is a spit formed?

Answer 17

Coastline changes in direction

Question 18

How does a spit get a recurved end?

Answer 18

Wind or wave direction changes

Question 19

Describe a bar?

Answer 19

Spit joins two headlands

Lagoon forms behind

Question 20

How are sand dunes formed?

Answer 20

Sand deposited by longshore drift is moved up the beach by wind.
Sand trapped behind a barrier such as berms or driftwood is colonised be plants- eg marram grass
Vegetation stabilised sand, more sand accumulates- embryo dunes

Question 21

What happens to sand dunes overtime?

Answer 21

Oldest dunes migrate inland as newer embryo dunes form.

Mature dunes can reach up to 10m

Question 22

Where do salt marshes develop?

Answer 22

River estuaries or behind spits

Question 23

Describe salt marshes?

Answer 23

Silt and mid deposits from river

Mudflats develop and colonised by halophytes

Question 24

How much is sea level rising by?

Answer 24

2mm a year

Question 25

Causes of eustatic and isostatic change?

Answer 25

Tectonic movement
Climate change
Isostatic uplift
Land subsidence

Question 26

Describe ria’s?

Answer 26

Partially submerged river valleys
Wide and gently sloping
Deepest at mouth and shallower in land

Question 27

Fjords description?

Answer 27

Depended glacial valley
Narrow and steep sided
Deep further inland

Question 28

What is a coastline with numerous islands parallel called?

Answer 28

A Dalmatian coastline

Question 29

Causes of coastal flooding?

Answer 29

Strong offshore winds 
Hurricanes 
Storm surges 
Tsunami 
High rainfall

Question 30

Hard engineering

Answer 30

Sea wall 
Rip rap
Groynes
Revetments 
Gabions

Question 31

Soft engineering

Answer 31

Beach nourishment
Sand dune regeneration
Coastal realignment
Creation of marshland