Part 3: Coastal change and conflict Flashcards
- What is erosion?
a. Where rocks are broken down
- What is the fetch?
a. How far a wave has been blown by the wind
- What is the swash of a wave?
a. How strongly it comes up the beach
- What is the backwash of a wave?
a. How strongly it washes back down the beach
- What are destructive waves?
a. Waves which erode beaches
- What are the characteristics of a destructive wave?
a. weak swash
b. strong backwash
c. long fetch
- What sort of beaches are formed by destructive waves?
a. Steep
- What are the characteristics of a constructive wave?
a. strong swash
b. weak backwash
c. short fetch
- What sort of beaches are formed by constructive waves?
a. Gently sloping
- What is longshore drift?
a. A process where sand and pebbles are transported along the coastline
- How does longshore drift work?
a. The swash of a constructive waves brings sand and pebbles up the beach
b. The back wash takes it back
c. Material moves in a zig zag along the coastline
- What are the four types of erosion?
a. Attrition
b. Abrasion
c. Hydraulic action
d. Solution (Corrosion)
- How does attrition work?
a. Rocks knock into each other and break
- How does abrasion work?
a. Waves throw sand and pebbles at cliffs
b. The cliff wears away
- How does hydraulic action work?
a. Large waves break against a cliff
b. Air in the cliffs is compressed
c. The rock weakens
d. The rock shatters
- How does solution work?
a. Water dissolves the rock e.g. limestone
- What are depositional coastal features?
a. when new coastal features are built by longshore drift and constructive waves
- What is deposition
a. when new sand or pebbles are dropped (deposited) on the coast by the sea
- What is longshore drift?
a. When the sea carries materials along the coast
b. Material is carried up the beach in the direction the wind is blowing
c. It goes back down the beach in a straight line
d. The process is repeated
- What is a spit?
a. a line of sand or pebbles across the mouth of a river or bay
- How is a spit formed?
a. Longshore drift carries sand and pebbles along the coast
b. Sea water slows down at the mouth of a river
c. Sea water deposits sand or pebbles in the mouth of the river
d. Sand and pebbles form a line across the mouth of the river
- Give an example of a spit
a. Spurn Point on the Holderness Coast
- What is a bar?
a. a line of sand or pebbles cutting off a bay from the sea
- How is a bar formed?
a. Longshore drift carries sand and pebbles along the coast
b. Sea water slows down at a bay
c. Sea water deposits sand or pebbles in the mouth of the bay
d. A spit is formed all across the bay
e. The bay is cut off from the sea and becomes a lagoon
- How are beaches formed?
a. Eroded material is transported by longshore drift
b. Deposited by constructive waves.
c. Beaches can be sandy or pebbly.
d. Steep pebble beaches are found in areas where erosion is taking place.
- What are concordant coastlines?
a. Coastlines with the same rock type eroded similar rate by the sea
- Which features are formed along concordant coasts?
a. Coves
- What are discordant coastlines?
- What are discordant coastlines?
- Which features are formed along discordant coasts?
a. Headlands and Bays
- Which landforms are created by erosion at the coast?
a. Caves
b. Arches
c. Stacks
d. Stumps
e. Wave cut platforms and cliffs
- How are caves, arches, stacks and stumps formed?
a. Form on headlands where the rocks are resistant
b. Destructive waves attack cracks in the rocks
c. Cracks erode to form a cave
d. The cave erodes to create an arch
e. The arch collapses and forms a stack
f. The stack erodes to form a stump
- How are wave cut platforms and cliffs formed?
a. waves attack the land forming cliffs
b. Hydraulic action and abrasion caused by the waves attacks the base of the cliff forming a wave cut notch.
c. The notch gets deeper creating an overhanging cliff.
d. The overhang collapses and creates piles of rock at the base of the cliff.
e. Waves remove the debris
f. Waves erode the new cliff face
g. The process repeats
h. The coastline retreats.
i. A wave cut platform is left at the bottom of the cliff.
- Give an example of an arch, stack and stump
- Give an example of an arch, stack and stump
- What sub-aerial processes at on the coastline?
a. Weathering
b. Mass movement
- What is weathering?
a. Weathering is the breakdown of rocks at or near the ground
- What are the three types of weathering?
a. Mechanical
b. Chemical
c. Biological
- What is mechanical (freeze thaw) weathering?
a. salty water gets into cracks in cliffs
b. water dries
c. crystals of salt form
d. as salt expands it breaks up the rock
- What is chemical weathering?
a. rainwater is slightly acidic
b. rain reacts with alkaline rocks (limestone/chalk)
c. the rocks are weakened
- What is biological weathering?
a. roots or burrowing animals deepen holes in the cliff
- What is mass movement?
a. Downward movement of rocks and soil from the cliff because of gravity
- What are the three types of mass movement?
a. Rock falls
b. Slumping
c. Sliding
- What is slumping?
a. rain seeps through the permeable layer of soil and rock
b. when it reaches impermeable layer of rock the rock and soil slumps and slips
- What is sliding?
a. similar to slumping
b. movement happens on a flatter surface or bedding plane
