Coasts EQ1 Flashcards
What is the littoral zone?
An area of shoreline where land is subject to wave action
How can we categorise coasts?
Rocky coasts + coastal plain
High energy + low energy
Erosional + depositional
Emergent + submegent
What is deltamic coast?
Dominated by river sediment
What is a reed coast?
Dominated by growth of coral
What is the back shore zone?
Above high tide level + only affected by waves during exceptionally high tides + major storms
What is the foreshore zone?
Where wave process occur between high + low tide margins
What is the nearshore zone?
Shallow water areas close to land + used extensively for fishing and leisure
What is the offshore zone?
The open sea
What is a coastal system?
Imputs energy from winds creates waves which hit the cliff causing it to erode
What is a discordant coastline?
Hard + soft rock run perpendicular to the coast
Creates bays and headlands
What is a concordant coastline?
Hard + soft rock run parallel to the coast
What is a Dalmatian coastline?
Bands of resistant rock along a concordant coastline w soft layers being eroded producing parallel islands
What is a haff coastline?
Different types of concordant coastline, found southern fringes of Baltic Sea
Long sediment ridges run parallel to coast just off shore creating lagoons
What is strata?
Layers of rock
What are bedding planes?
Horizontal cracks
Lines of weakness caused by gaps in time during period of rock formation
What are joints?
Vertical cracks
Caused by contractions as sediments dry out
What are faults?
Formed when stress exceeds internal strength causing it to move
What are folds?
Formed by pressure during tectonic activity
Presses together
What is seaward dripping strata?
Strata pointing down to the sea
Lots of landslides
What is landward dipping strata?
Strata that points down away from the sea towards the base of the cliff
Steep overhanging sections
What is horizontal strata?
Horizontal layers of rock
What are characteristics of igneous rock?
Crystalline
Resistant
Impermeable
What are examples of igneous rock?
Granite
Diorite
Basalt
Can be found in Cornwall
What are the recession rates of igneous rock?
1mm/yr or less
What are characteristics of metamorphic rock?
Hard
Resistant
Impermeable
What are examples of metamorphic rocks?
Marble
Schist
Slate
Can be found in Scotland
What are the recession rates for metamorphic rocks?
1mm-1cm/yr
What are the characteristics of sedimentary rocks?
Permeable
Jointed
Some porous
What are examples of sedimentary rocks?
Sandstone
Limestone
Chalk
Shale
Can be found in Dorset and Devon
What are the recession rates for sedimentary rocks
1cm-1m/yr
Or
1mm-1cm/yr
What is unconsolidated materials?
Boulder clay
Lose and easily eroded
If compacted particles stick together form impermeable layer
What are examples of unconsolidated materials?
Holderness coastline
1-10m/yr
How does vegetation stabilise coasts?
Roots of plants-bind particles together= harder to erode
Plants cover surface of sediment- act as protective layer avoiding exposure to moving water
Plants act as obstacles- reduce wind speed
How does sand dune succession occur?
- Sand gathers around obstacle on strand line
- Hardy plants colonise on small embryo dunes
- Small dunes grow into large fore/yellow dunes as more sand accumulates
- After series of plants changes, climate community reached marks end of succession
What is salt marsh succession?
Coastal wetlands flooded and drained by salt water brought by tides
Marshy as soil composed of deep mud and peat is waterlogged and spongy
Creates salt marsh
