Coasts - 2B.1

Question 1

Coast definition

Answer 1

the land adjacent to the sea and is often heavily polluted and urbanised

Question 2

Backshore definition

Answer 2

Above the high tide level and is only affected by waves during high tide and major storms

Question 3

Foreshore definition

Answer 3

wave processes occurs between low and high tide marks

Question 4

Nearshore definition

Answer 4

shallow water areas close to land and used exclusively for fishing, coastal trade and leisure

Question 5

Offshore definition

Answer 5

The open sea

Question 6

The coast is a system…

Answer 6

it has inputs, outputs and processes which are balanced and equal. Because they are in a dynamic equilibrium (ever changing, never in a constant state)

Question 7

Coastal inputs

Answer 7

• people (human activity, coastal management)
• land (rock type and structure, tectonic activity)
• marine (waves, tides, storm surges)
• atmospheric (weather/climate, climate change, solar change)

Question 8

Coastal outputs

Answer 8

• erosional landforms (arch, stack, stump, bay, headland)
• depositional landforms (tombolos, spits, beaches)
• different types of coast (coastal wetlands and sandy beaches)

Question 9

Coastal processes

Answer 9

• deposition - dropping off of sediment
• transport - movement of sediment
• weathering - wearing away of material in situ
• erosion - wearing away of material
• mass movement - movement of surface material

Question 10

What are coasts?

Answer 10

the narrow zone where the land and sea interact

Question 11

Types of coastline: rocky vs coastal plains

Answer 11

This is the most straightforward type of classification

Question 12

Rocky coastlines

Answer 12

cliffs, with visible rocks and break in the angle of the beach

Question 13

Coastal plains

Answer 13

gentle and the edge of the littoral ones can be hard to distinguish. Often fins dunes on sandy beaches when they aren’t underwear and they give a hint about a boundary

Question 14

Rocky cliff profiles: sub-aerial dominated

Answer 14

• most erosion is done by surface processes (wind, rain, rivers etc)
• cliff tends to be curved with accumulated debris at the base of the cliff and a little undercutting

Question 15

Rocky cliff profiles: marine dominated

Answer 15

• most erosion is done by the sea
• abrupt transition from land to sea
• steep cliff with undercutting (wave-cut notch)
• little beach, mainly rocks revealed at low tide (wave cut platform)

Question 16

Coastal plains

Answer 16

• low lying areas, generally containing sand dunes, marshes and wetlands
• form sue to a fall in sea level exposing what was a shallow continental shelf or due to accretion (build up) by material dropped by rivers
• dependant on a state of dynamic equal

Question 17

Long term - geology

Answer 17

• classify - rocky, sandy, estuarine, concordant, discordant
• land characteristics
• lithology (rock type)
• structure (arrangement of rock units)

Question 18

Long term sea level change

Answer 18

• classify - emergent and submergent coastline
• Caused by: Tectonic processes (lift sections of land = local sea fall. Land subsides = local sea rise) and Climate change (sea level rise - emerging from ice age and surface ice melts. Sea level fall - 90,000 years during glacials)

Question 19

Short term - energy inputs

Answer 19

• receive energy from tectonic currents, mass movement, tides (ebb and flow over a 12-15 hour cycle), gravity, waves (main input)
• classify - high and low

Question 20

advancing/retreating coastlines

Answer 20

• long term processes - emergent/submergent

- short term processes - erosion/deposition

Question 21

Sediment inputs

Answer 21

• get sediment from tides, waves, wind (vary constantly), currents, mass movement, tectonic processes
• Added to a coastline (deposition), removed (erosion)

Question 22

Eroding coastline

Answer 22

erosion > deposition
net loss of sediment
coastline retreats

Question 23

deposition coastline

Answer 23

deposition > erosion
net gain of sediment
coastline advances

Question 24

Littoral zone definition

Answer 24

the wider coastal zone including adjacent land areas and shallow parts of the sea just offshore

• exposed to the air at low tide and is under water at high tide
• the back shore and foreshore areas are where physical processes and the greatest amount of human activity occurs