2B.1

Question 1

Define littoral zone

Answer 1

An area of coastline which has all sediment processes occurring sources, transport and sinks. A littoral cell is not a closed system

Question 2

What does the littoral zone consist of

Answer 2

backshore, nearshore, offshore zones and includes a wide variety of coastal types - it is a dynamic zone of rapid change
OKAY NOW FRY BACON (SEA - OFFSHORE, NEARSHORE, FORESHORE BACKSHORE)

Question 3

What is the backshore

Answer 3

• The upper beach closest to the land, including any cliffs or sand dunes.
• essentially from the mean high tide water mark up to a change in physiography (sand dune or cliff)

Question 4

What is the foreshore

Answer 4

The lower part of the beach covered twice a day at high tide (the part of the beach that receives the most regular wave action).
- it includes the swash zone

Question 5

What is the nearshore

Answer 5

• area from the mean low tide mark to beyond where waves break (hence called the breaker zone)
• this part of the sea is not exposed unless there is low tide unlike the foreshore which is exposed at both high and low tide

Question 6

What is the offshore zone

Answer 6

• open sea
• further seaward than nearshore
• The area of deeper water beyond the point at which waves begin to break. Friction between the waves and the sea bed may cause some distortion of the wave shape.

Question 7

What is wave breaking

Answer 7

Waves break, but vary between high and low tide points

Question 8

What is a wave

Answer 8

• Initially in open water, as energy transferred from air to water
• Shelving increases friction and wave breaks

Question 9

What do rocky coasts result from and why?

Answer 9

Rocky coasts (high and low relief) result from resistant geology
WHY …
withstands erosive forces of sea, rain and wind, often in a
high-energy environment

Question 10

What is resistance of a rock dependent on?

Answer 10

1) is rock clastic or crystalline?
2) how many cracks, fractures and fissures?
3) lithology of a rock

Question 11

Why does clastic/crystalline factors matter to rock resistance

Answer 11

• sedimentary rocks like sandstone are clastic as they
  are made up of cemented sediment particles, therefore are vulnerable to erosion,
• igneous and metamorphic rocks are made up of interlocking crystals, making them more
  resistant to erosion

Question 12

why does the amount of fissures, cracks and fractures affect resistance of geology?

Answer 12

the more weaknesses there are in the rock
the more open it is to erosional processes, especially Hydraulic Action

Question 13

Igneous; State examples, rate of erosion

Answer 13

examples: granite, basalt
ROE: v slow, less than 0.1 cm a year

Question 14

SEDI; State examples, rate of erosion

Answer 14

example is limestone
ROE = very fast, 0.5-10 cm year

Question 15

metamorphic ; State examples, rate of erosion

Answer 15

examples: slate, schist, marble
ROE = slow, 0.1-0.3 cm a year

Question 16

Why does age of rock affect its resistance to erosion

Answer 16

• Ancient limestones have been compressed and compacted over millions of years = more resistant
• Recently erupted volcanic lava flows and tephra deposits tend to be weaker and easily eroded = less resistant

Question 17

How does permeability affect resistance to erosion

Answer 17

• Permeability is important as groundwater flow can weaken rocks by exploit joint structures and binding materials.
• It can also create high pore water pressures within cliffs reducing stability

Question 18

State examples of permeable and impermeable rock

Answer 18

Permeable rocks include sandstones and limestones
Impermeable rocks includes clays, mudstones and most igneous and metamorphic rocks

Question 19

Describe unconsolidated material and how it is affected by erosion

Answer 19

• unconsolidated coastal material is the weakest and most easily eroded (due to lack of strength and subsequent exploitation by water).
• They tend to slump when saturated.
• consider if there are reactive Minerals in the rock (e.g. Calcite) – solution.

Question 20

Define differential erosion

Answer 20

The selective erosion of areas of weaknesses