Coasts

Question 1

What is a coast?

Answer 1

where the land meets the sea.

Question 2

What are high and low water marks the result of?

Answer 2

high and low tides.

Question 3

What is the area between the high and low water marks called?

Answer 3

the shore.

Question 4

What are waves a result of?

Answer 4

friction between the wind and the surface of the sea.

Question 5

What three things affect the size of a wave?

Answer 5

wind speed
length of time wind blows in same direction
lenth of sea where wind blows (fetch of wave)

Question 6

What is the top of a wave called?

Answer 6

a wave crest.

Question 7

What is the bottom of a wave called?

Answer 7

a wave trough.

Question 8

What is swash?

Answer 8

the wave that rushes onto a beach.

Question 9

What is backswash?

Answer 9

wave that goes back into the sea after rushing on to a beach.

Question 10

What are four features of destructive waves?

Answer 10

weak swash
strong backswash
high/steep
remove material from beach

Question 11

What are four features of constructive waves?

Answer 11

strong swash
weak backswash
builds up the beach
low waves

Question 12

What is longshore drift?

Answer 12

movement of sediment along a beach.

Question 13

What are groynes?

Answer 13

barriers that trap sediment and reduce longshore drift.

Question 14

What are cliffs and wave-cut platforms?

Answer 14

vertical or steeply sloping rocks

Question 15

Where is a wave cut notch on cliffs and wave-cut platforms?

Answer 15

high tide level

Question 16

How is a wave-cut platform formed?

Answer 16

the retreat of a cliff.

Question 17

What are three features of headlands?

Answer 17

• projects out into the sea
• is usually longer than its breadth
• has sides which form cliffs

Question 18

What are four features of bays?

Answer 18

• an approximately semi-circular shape of sea extending into the sea
• a wide open entrance from the sea
• land behind it that is lower than the headlands on either side
• form on discordant coasts

Question 19

What are discordant coasts?

Answer 19

coasts that have different types of rocks at 90 degrees to the sea.

Question 20

Where do arches and stacks form?

Answer 20

discordant coasts.

Question 21

How are arches, caves, and stacks formed?

Answer 21

wave refraction.

Question 22

What are beaches composed of?

Answer 22

sand, shingle, or both.

Question 23

How is material on a beach sorted?

Answer 23

fineness.

Question 24

How are spits formed?

Answer 24

• prevailing wind
• longshore drift
• deposition builds up/repeated
• onshore winds

Question 25

What is a spit called if it totally blocks a bay?

Answer 25

a bar.

Question 26

What is the water behind a bar called?

Answer 26

a lagoon.

Question 27

What forms in the waters behind a spit?

Answer 27

a saltwater marsh.

Question 28

What do salt marshes become in tropical sheltered waters?

Answer 28

mangrove swamp forests.

Question 29

How do salt marshes and mangrove swamps provide protection for the coast?

Answer 29

• preventing erosion
• allow a space for deposition to take place
• giving the water a gentle place to settle

Question 30

How do salt marshes and mangrove swamps provide protection for the land?

Answer 30

• protects against hurricanes/floods

Question 31

How do salt marshes and mangrove swamps provide protection for the sea?

Answer 31

• filters chemicals
• mud can collect there

Question 32

How do salt marshes and mangrove swamps provide an important habitat?

Answer 32

• saltwater plants and mangroves can only grow there
• many birds + fish thrive in those conditions

Question 33

How do salt marshes and mangrove swamps provide a recreational resource?

Answer 33

• fishing
• bird watching
• boating

Question 34

What are stilt roots?

Answer 34

mangrove roots that anchor the plant in the soft mud and slow down water movement.

Question 35

What are sand dunes?

Answer 35

ridges of sand which form at the bank of beaches and on spits.

Question 36

How are sand dunes formed?

Answer 36

1) obstacle on beach
2) friction with obstacle slows onshore wind so sand is deposited around the obstacle
3) embreyo dunes form and join in a line called a fore dune
4) moves inland
5) dune becomes semi-fixed grey dune
6) dune becomes fixed dune

Question 37

Where do lines of dunes form?

Answer 37

parallel to the sea.

Question 38

What is marram grass?

Answer 38

grows on dunes
resistant to drought
network of long roots
slows wind and protects sand dunes from erosion

Question 39

Why are semi-fixed dunes grey?

Answer 39

because of the humus from plant decay.

Question 40

How can you tell which dunes are the oldest?

Answer 40

further inland = older

Question 41

What does an increase in the depth of soil of a dune do?

Answer 41

more humus content
more water retention

Question 42

What are the pHs of young and old dunes?

Answer 42

young dunes - alkaline
old dunes - acidic (rainwater leaches nutrients)

Question 43

What are slacks?

Answer 43

long, marshy depressions that lie between dune ridges and contain water-loving plant species.

Question 44

What is a blowout?

Answer 44

a depression in a sand dune caused by wind removing exposed sand.

Question 45

Where are coral reefs found?

Answer 45

between latitudes 30* north and 30* south.

Question 46

Where do coral reefs grow?

Answer 46

below low tide level.

Question 47

What do coral reefs need to thrive?

Answer 47

oxygen, food, clear/clean water, high salinity, sunlight.

Question 48

What are the three types of coral reefs?

Answer 48

Fringing reef - right around the isalnd
Barrier reef - slightly off the island coast
Atoll - in a circle not around an island