Coasts (Case studies)

Question 1

An example of a “lost village”

Answer 1

Hallsands, Devon

Question 2

Write up the story of Hallsands as a “lost village”

Answer 2

• In the late 19th century, Hallsands was a small coastal fishing village with a close-knit community. The village thrived on the local fishing industry
• In the early 20th century, plans to expand the naval dockyard at Keyham, Plymouth led to approved plans to dredge shingle from Hallsands.
• The removal of shingle altered the coastal dynamics leading to increased erosion of Hallsands protective beach
• in 1900, a storm struck the area. the high energy, powerful waves were unable to be absorbed by the diminished beach and the sea surged through the village.
• Houses were destroyed, the community was on the brink of collapse. Subsequent storms in 1917 and 1921 further intensified the damage, leaving Hallsands in ruins.

Question 3

Give an example of a recurve:

Answer 3

Hurst castle spit, Hampshire.
- Formed by low energy conditions behind the spit causes sediment to build up in the form of a recurve

Question 4

Where are barrier islands common?

Answer 4

• 10-15% of the world’s coastlines are made up of barrier islands, being particularly common in mid- low latitudes
• Lots on the east coast of the USA

Question 5

Example of a bar/barrier beach

Answer 5

Start Bay and Slapton Ley Lagoon
-9km long and has been formed around shingle deposits

Question 6

Physical factors at play on the Holderness coastline

Answer 6

Weather - Winter storms produce stronger waves and higher sea levels. The rain they bring intensifies sub aerial processes.
Waves - Dominant waves from the north east, also the direction with the longest fetch. Attacks the foot of the cliff, removing clay in suspension. LSD then carries this material southward.
Geology - Chalk and boulder clay are the main types of rock, chalk more resistant to erosion and has created classic features at Flamborough head

Question 7

Coastal defence scheme along the Holderness coast.

Answer 7

• Mappleton
• 2 rock groynes, revetment, regrading of cliffs to reduce slumping and beach nourishment.

Question 8

Holderness cliffs

Answer 8

• Boulder clay cliffs, retreating at an average rate of 1.8m per year. (10x that of the chalk cliffs)
• Rainwater enters the clay and the weight of water causes material to slide seawards.
• At the cliff foot the fine clay is easily removed by waves, adn it is estimated that LSD carries half a million tonnes of sediment southwards each year in suspension.

Question 9

Geology of Jurassic coast

Answer 9

Bands of alternating geology, discordant and concordant coastlines can be seen.
- Headlands and bays, and coves and bars on concordant areas.

Question 10

Sand dunes found along the Jurassic coast

Answer 10

• Studland sand dunes.

Question 11

CASS sequence

Answer 11

Old Harry
- Wave refraction causes erosion of the headland and deposition in the bays either side.
- Cracks in the chalk are expanded due to hydraulic action and freeze thaw. Forming caves, opening up to form arches, collapse of arches = stacks.

Question 12

Swanage Bay

Answer 12

• A bay formed between two headlands. This is because sands and chalk between two bands of resistant rocks erode at a faster rate via hydraulic action, abrasion and attrition.