costal landforms

Question 1

bays and headlands:
the key to their formation is the differences in geology (the differences and types of hardness of rocks). these are found in alternating hard and softer rock

what are 2 types of coastlines called?

Answer 1

1. concordant coastline

2. discordant coastline

Question 2

differences between concordant and discordant coastlines?

Answer 2

concordant - lie parallel to the coastline
discordant - have alternate layers of rock that lie at right angles to the sea (the other side) (not the front but the side of the cliff)

Question 3

describe the creation of a wave-cut platform

Answer 3

high energy waves undercut the base of the cliff, this creates a wave cut notch (´cave` in the cliff). continual undercutting enlarges the notch. the unsupported rock above the notch eventually collapses.
the rocks and debris is gradually washed away. over time the cliff retreats inland, leaving a gently-sloping wave-cut platform.

( the wave-cut platform is exposed at low tide and is covered by water in high tides.)

Question 4

caves, blowholes, arches, stacks and stumps

describe formation

Answer 4

weaknesses occur in a headland or cliff (cracks), overtime these weak areas are widened through the precesses of weathering and erosion. a cave then may form. if vertical erosion also occurs a blowhole may result. if the erosion carries on it will completely break through the cave, creating an arch. if the roof of the arch can no longer be supported it will collapse. this forms a stack at the end of the headland. over time the base f the stack will be eroded by wave action, the stack will eventually collapse and leave a small stump behind.

Question 5

explain and describe the formation of spits:

Answer 5

A spit is a permanent landform. they occur when long shore drift is happening and there is a sudden change of the coastlines shape. at the position where the coastline suddenly changes direction sand is deposited, an accumulation of sand occurs at this point. LSD continues and carries on depositing sand and shingle. this leads to the formation of a long narrow strip of sand. one end is attached to the land while the other projects across the bay. slowly further deposition allows the spit to build up to sea level. if the prevailing wind changes for an extended period of time eg. the opposite side as before then a hooked shape will form. in the sheltered area behind the spit a salt marsh will be formed.

Question 6

what is a salt marsh?

Answer 6

A salt marsh is ecologically beneficial as it provides an ideal breeding site for many fish and bird species.

Question 7

explain and describe the formation of a bar:

Answer 7

if a strong river current is present then the spit will be unable to grow entirely across the bay. (deposition of sand is prevented) if no large river exists in the bay the spit will continue to grow right across the bayy leading to the formation of a BAR

( a protected LAGOON will be created behind the bar)

Question 8

what are the 4 factors affecting the coastal environments?

Answer 8

1. geology
2. vegetation
3. sea level changes
4. people