coastal landscapes

Question 1

define fetch

Answer 1

the distance the wind blows across the water

Question 2

define swash

Answer 2

the movement of water up a beach

Question 3

define backwash

Answer 3

the movement of water down the beach

Question 4

what is the crest?

Answer 4

the top of the wave

Question 5

what is the trough?

Answer 5

the lowest point of the wave

Question 6

define wave height/ amplitude

Answer 6

the height difference between the wave crest and the neighbouring trough

Question 7

define wavelength

Answer 7

the distance between successive wave crests

Question 8

what is the wave period?

Answer 8

the time for one wave to travel the distance of one wavelength

Question 9

give 4 features of constructive waves

Answer 9

1. low wave amplitude
2. long wavelength
3. low frequency (6-8/min)
4. breaking waves spill forward

Question 10

give 4 features of destructive waves

Answer 10

1. high wave height
2. steep form
3. high frequency (10-14/min)
4. breaking waves spill downward

Question 11

what type of beach do contstructive waves cause?

Answer 11

gentle inclined as waves break forwards

Question 12

what type of beaches do destructive waves cause?

Answer 12

rapidly steepening as waves plunge down

Question 13

where does energy become concentrated on in wave refraction?

Answer 13

the headland

Question 14

why do waves refract as they hit shallow water?

Answer 14

as the back of the wave in the deeper water does not slow like the front, causing the wave to bend.

Question 15

what is a tide?

Answer 15

a periodic rise and fall in the sea level

Question 16

what is the cause of tides?

Answer 16

the gravitational pull of the sun and the moon

Question 17

why does the moon have a greater influence on tides than the sun?

Answer 17

as it is far nearer.

Question 18

how often is the spring tide?

Answer 18

twice a lunar month

Question 19

what occurs during the spring tide?

Answer 19

the sun, moon and sun are all in a line causing the strongest tidal force

as well as the highest monthly tidal range

Question 20

how often is the neap tide?

Answer 20

twice a month

Question 21

what occurs during the neap tide?

Answer 21

the sun and moon are at 90 degrees in relation to the Earth

Question 22

what does the neap tide result in?

Answer 22

the lowest monthly tidal range with high and low tides 10-30% lower than average.

Question 23

what is the tidal range?

Answer 23

the differnce in sea level at high and low tide

Question 24

what do tidal ranges determine?

Answer 24

the upper and lower limits of erosion and deposition

Question 25

what causes tidal surges?

Answer 25

when meteorlogical conditions cause strong winds which can produce a much higher sea level.

Question 26

what system is a coastal system?

Answer 26

an open system

Question 27

what is a dynamic equilibrium?

Answer 27

inputs and outputs of a system are in balance

Question 28

what is feedback?

Answer 28

where a component upsets equilibrium, changing a systems features

Question 29

what is the negative feedback mechanism?

Answer 29

if one component changes another will do the opposite to maintain equilibrium.

Question 30

what is a current?

Answer 30

the permanent or seasonal movement of surface water in the sea or ocean

Question 32

what is a longshore current?

Answer 32

a flow of water parallel to the shore, moving water along the surf zone while transporting sediment. | caused by waves coming in at an angle

Question 33

what is the surf zone?

Answer 33

the area between where the waves break and where the water moves up the beach as swash.

Question 34

what is a rip current?

Answer 34

strong current which move away from the shore.

Question 35

how are rip currents formed?

Answer 35

where incoming waves cause of pile up of water, water may flow parallel to the shore until it flows out the breaker zone.

Question 36

what is the breaker zone?

Answer 36

the area where approaching waves begin to break | often water depth is 5-10m

Question 37

what is upwelling?

Answer 37

where cold, deep and nutrient rich ocean water is forced to the surface to replace the pushed away surface waters.

Question 38

name 4 sources of sediment

Answer 38

1. streams or rivers which flow into the sea 2. cliff erosion 3. offshore sandbanks 4. material from biological origins

Question 39

what is a sediment cell?

Answer 39

a distinct area of coastline serparated from other areas by well defined boundaries e.g headlands and deep water

Question 40

what are sediment cells divided into?

Answer 40

sub cells

Question 41

what occurs at sediment cells?

Answer 41

the movement of sediment resulting in depositional features

Question 42

what is the coastal sediment budget?

Answer 42

the balance between sediment being added to and removed from a system | how much sediment comes in and out ## Footnote defined within each sediment cell

Question 43

how is the sediment coastal budget kept in balance?

Answer 43

through erosional and depositional processes

Question 44

what is a sub aerial process?

Answer 44

land based processes which affect the shape of the coastline | e.g weathering, mass movement and run off

Question 45

what is traction?

Answer 45

large boulders and stones being rolled and slid along the sea bed in high energy environments

Question 46

what is saltation?

Answer 46

small stones bouncing or leapfrogging along the sea bed or beach in high energy conditions?

Question 47

during saltation what may be dislodged?

Answer 47

falling, previously thrusted particles may dislodge other particles causing more bouncing movements.

Question 48

what is suspension?

Answer 48

very small particles are carried and picked up by moving water and its turbulences.

Question 49

what can suspension result in?

Answer 49

murky water

Question 50

what is solution?

Answer 50

dissolved materials being transported in the mass movement of the water.