Coasts

Question 1

Feedback at the coasts

Answer 1

Negative (usually temporary)- change causing opposite effects - beach eroded -> cliffs eroded -> sediment deposited beach grows again

Positive (long term)- change has similar effects - beach forms slows waves down -> more sediment deposited increasing beach

Question 2

Energy Sources

Answer 2

Wind - high to low pressure

Waves - constructive and destructive

Tides and currents

Question 3

sediment sources

Answer 3

Rivers - sediment from inland

Sea level rise-forms estuaries

Erosion - waves/weathering

Offshore deposits - waves, tides, currents

sediment budget - difference between input and output

Question 4

Erosion

Answer 4

abrasion - rocks thrown at cliffs

hydraulic action - air in cracks compressed

wave quarrying - energy from wave

corrosion - soluble rocks dissolved in water

attrition - rock on rock into smaller bits

Question 5

Transportation

Answer 5

Traction - large boulders pushed

Saltation - pebbles bounced

suspension - silt carried

solution - dissolved in water

Question 6

Sub-aerial Weathering

Answer 6

Salt weathering - salt crystals cause pressure on rock

Freeze-thaw - water freezes and expands weakening rock

Chemical - acid rain dissolves rock

Wetting/Drying - clay expands when wet

Question 7

Mass movement

Answer 7

Slides - straight line

Slumps - curve

Rockfalls

Mudflows

Question 8

Erosion Landforms

Answer 8

Cliffs and Wave Cut Platforms

Headlands and Bays

Cave, Arch, Stack, Stump

Question 9

Deposition landforms

Answer 9

Beaches

Spits

Bars

Barrier island

Sand dunes

Mudflats and Saltmarsh

Question 10

Sea level change

Answer 10

Eustatic - change in volume of water or shape of ocean basin - Climate change and Tectonic movements

Isostatic- vertical movements relative to the sea - uplift/depression from ice sheet weight, Tectonic (subduction)

Question 11

land forms at emergent coastline

Answer 11

Raised beaches - above high tide mark

exposed wave cut platforms

Relict cliffs - vegetated, caves, arches, stacks all up the cliff

Question 12

land forms at submergent coastline

Answer 12

Rias - river valleys partially submerged

Fjords - drowned glacial valleys

Dalmatian coastline - islands parallel to coastline after parallel valleys are flooded

Question 13

coastal management

Answer 13

Hold the line - maintain existing defences

Advance the line - defences further out to sea

Do nothing - deal with as it happens

Managed realignment - managed retreat flooding less worthy land

Question 14

Hard engineering

Answer 14

Sea wall - expensive and creates backwash eroding under the wall

Gabions - Expensive strong backwash again

Riprap (boulders piled) - fairly cheap but shift in storms

Groynes - cheap but reduces sediment down the coast

Question 15

Soft engineering

Answer 15

Beach nourishment

Dune regeneration

coastal realignment

Land use management

Question 16

Sustainable management plans

Answer 16

Shoreline management plans
-coastline split into sediment cells - managed accordingly (local authorities in one cell)

Integrated Coastal Zone Management (ICZM)
- considers all elements of coastal system (land, water, people, economy)
- protect coast in natural way
- environment as a whole (land/water together)
- uses considered (fishing, industry, tourism)
- local, regional, national all have input
- dynamic strategy (reevaluated to meet demands/change)