Coasts 4 markers

Question 1

Explain the development of salt marshes

Answer 1

• Develop in sheltered estuaries behind spits, as spit develops area behind becomes sheltered
• Silt is deposited which builds up over time to form a mudflat, this continues and rises above sea level
• Halophytic vegetation is adapted and colonises mud which traps sediment

Question 2

Explain the development of barrier beaches

Answer 2

• LSD moves along coastline until change in coastline
• This forms a spit and when goes across whole bay barrier beach forms (between 2 headlands)
• Not likely to form in estuaries due to force of freshwater
• Colonisation can stabilise barrier beach (mangroves)

Question 3

Explain the development of sand dune environment

Answer 3

• Formed when sand deposited by LSD is moved up beach by wind
• Sand is colonises by plants (marram grass)
• Vegetation stabilises and makes conditions less hostile and more sand accumulates
• Sand dunes are formed

Question 4

Outline processes which leads to development of spits

Answer 4

• LSD deposits material across river mouth
• Occurs when coastline changed direction
• Wind can curve the spit and form compound spit
• Area behind can form mudflats/salt marshes and barrier beach

Question 5

Process of LSD in development of coastal landscapes

Answer 5

• LSD is sediment moving along coastline (swash is parallel to wind direction backwash is straight down)
• Lead to formation of a spit/ barrier beach
• Can be stopped by groins

Question 6

Outline process of subaerial weathering in development of coastal landscape

Answer 6

• Salt crystallisation, pressure on rock and breaks off
• Freeze thaw, weakens rock and pieces fall off
• Wetting/drying, fragments break off from pressure