Enquiry Question 2 Flashcards

Question

How are wave cut platforms formed?

Answer 1

The wave erodes the cliff between low and high tide - inter tidal zone. This creates a wave cut notch. Then erosion means the rock above the notch is unsupported and collapses leaving a gently sloping rocky platform.

Answer 2

1. A weakness occurs in the headland in the form of a crack or fault. 2. The waves erode the base of the crack which forms a cave. 3. The back of the cave is eroded to create an arch. 4. The base of the arch is eroded to create a wave cut notch leaving the rock above unsupported so it collapses. 5. The roof of the arch is eroded by chemical and biological processes and the arch becomes wider until the roof collapses. 6. This leaves a stack. 7. The base of the stack is eroded to create a wave cut notch, the rock above collapses leaving a stump.

Answer 3

The waves enter the beach in the direction of the strong prevailing wind. The swash is strong and the backwash is weak so the waves deposited material. This process continues so that sediment is transported in the direction of the wind.

Answer 4

The energy from waves are mainly absorbed by headlands where sediment is eroded. This sediment is then deposited on the beach by constructive waves and long shore drift.

Answer 5

Longshore drift moves sediment along the coastline. A sudden change in the coastline is needed for a spit to occur. Behind a headland there is a sheltered area where deposition occurs. The heaviest largest material is dropped first by the headland. Gradually smaller sediment is dropped and the spit grows. A secondary wind direction creates a secondary long shore drift direction to create a recurred end to the spit. Waves don't reach behind the spit so water calmer and deposition creates salt marshes. The spit won't reach all the way across the bay because of the deep water and river currents.

Answer 6

A bar is formed when a spit encounters no change in wind direction or movement of water so it grows until it reaches the other headland of the bay forming a bar and a lagoon behind it.

Answer 7

Swanage is in the south of the U.K. on the coast. It is south of Bournemouth and has 3 bays and 2 headlands.

Answer 8

About half of Swanage bay is built up and defended because of tourism. Sea defences include groynes and a sea wall. North of Swanage to Ballard point and the Foreland the beach gives way to limestone cliffs because no sediment is being transported their as it is all kept at the south of Swanage bay.

Answer 9

Swanage is in the south of the UK on the coast. It is south of Bournemouth and has 3 bays and 2 headlands. Swanage bay is to the east of Swanage and north of Durlston head.

Answer 10

Over 20million people live within the coastal zone. At Holderness for example, over 29 villages have been lost to coastal erosion in the last 1000years.

Answer 11

Structures like groynes are built to trap sand on and protect tourist beaches. However removing sediment from the system results in increased erosion further along the coast.

Answer 12

Roads, railways, oil refineries, chemical plants and ferry and shipping ports are located along the coast. The ESSO oil refinery at Fawley near Southampton is the largest in the U.K. It handles over 2000 ships a year, transporting 22 million tonnes of crude oil. Large cities and industrial areas have high economic value and are often protected with hard engineering.

Answer 13

In 1897 over 600,000 tonnes of gravel were dredged from the sea bed to build Plymouth Docks in Devon. Soon after wave action eroded the 5metre high wall that was protecting nearby Hallsands village, which was then destroyed by storms in 1917.

Answer 14

Sea level rise and erosion is already leading to the loss of agricultural land and could affect the fishing industry in area such as the Exe estuary in Devon. Land used for agriculture has a low economic value and isn't protected.