Systems and processes

Question 1

wind

Answer 1

• Wind blows across the sea surface- transfers Kinetic energy
  -Stronger wind= more energy= more powerful waves
  -Prevailing wind- most common wind direction -affects dominant wave directions
  Fetch- Distance the wind travels over open water- longer fetch, larger waves

Question 2

Constructive waves

Answer 2

-Low energy
-Swash is strong
-Backwash is weak
-Deposits material
-Builds up a beached (gentle slope)

Question 3

Destructive Waves

Answer 3

-High energy
-Swash is weak
-Backwash is strong
-Erodes and removes material
-Breaks down beaches (steep slope)

Question 4

Tides

Answer 4

-Tides are the periodic rise and fall of sea level caused by the gravitational pull of the moon and the sun
-High tide- water reaches further up the beach erosion more possible
-Low tide- exposes more of the shore
-Tidal range- The difference between high and low tide
-Influences where wave action occurs on the coast

Question 5

Currents

Answer 5

-Longshore current- moves parallel to the coast due to waves hitting at an angle
Key to longshore drift (sediment transport)
-Rip current- strong, narrow currents moving away from the beach, often in a seaward direction. Dangerous to swim
-Upwelling- deep, cold water rises to the surface- important for marine life, but less relevant to coastal shaping

Question 6

High energy coast

Answer 6

-exposed to powerful waves (often from prevailing winds)
-Typically, erosional landforms dominate
-Strong winds, long fetch and frequent storms
-more wave energy than sediment supply
-Often rocky coastlines and steep cliffs
-Erosion = hydraulic action, abrasion, corrosion
-Transportation = longshore drift can be strong
-Landforms: Headlands and bays, wave-cut platforms, Arches, stacks and stumps and cliffs

Question 7

Low energy coast

Answer 7

-Sheltered from strong waves (e.g. estuaries, bays)
-Deposition dominates over erosion
-Short fetch, gentle winds, and calm conditions
-High sediment availability (from rivers or longshore drifts)
-Coastal plains, river estuaries
-Deposits- sediment accumulates due to weak wave energy
-Limited erosion
-often shallow gradient beaches
-Landforms = beaches, spits, Bars and tombolos, Salt marshes and mudflats and sand dunes

Question 8

Weathering

Answer 8

The breakdown of rock in situ (without movement)
-Mechanical/Physical: breakdown without chemical change
-Chemical: Breakdown via chemical reactions
-Biological: Plants or animals break down rock
Leads to weakened cliff faces, increasing the chance of mass movement

Question 9

Mass Movement

Answer 9

The movement of weathered material downhill due to gravity
-Rockfall: Sudden collapse of rockes
-Slumping: Saturated material slumps along curved surfaces
-Landslide: Blocks of rock slide down in a straight line

Question 10

Marine Erosion

Answer 10

The wearing away of the coastline by the sea
-hydraulic action: force of water compresses air in cracks
-abrasion (corrosion): pebbles scrape against cliffs
-attrition: Rocks collide and smooth over time
-Solution (corrosion): Acids dissolve rock (especially chalk/limstone.
Creates features like wave-cut platforms, caves, arches and stacks.

Question 11

Transportation

Answer 11

The movement of sediment along the coast by the sea
-Longshore drift: Swash moves sediment diagonally; Backwash pulls it straight down
-Traction: Large pebbles roll along the seafloor
-Saltation: small pebbles bounce along the bed
-Suspension: Fine sediment carried in the water
-Solution: Dissolved material is carried in the water
Longshore drift is responsible for spit and bar formation