Topic 2: Coasts Flashcards
(15 cards)
What is the littoral zone?
The littoral zone refers to the coastal area that is affected by waves.
What are the 4 components of the littoral zone?
- Backshore
- Foreshore
- Nearshore
- Offshore
What is the backshore?
Sits above the high tide level, coastal processesonly affect it in extreme weather conditions.
What is the foreshore?
Between high and low tide, where many wave processes take place.
What is the nearshore?
Area just off the coastline beyond the low tide level, consists of shallow sea water.
What is the offshore?
The open sea where waves start to break and water is deeper.
How do long term changes create coastlines?
Tectonic processes causing emerging or submerging coastlines
Rocky or estuarine coastlines are created depending on geological resistance.
Concordant or discordant depending on relative position of geological strata and wave action.
How do short term changes create coasts?
Coasts are classified by their tidal range
retreating or advancing coasts depend on what process dominates the site.
High or low energy depends on balance between erosion and deposition.
primary or secondary coasts depend on it being dominated by land or marine based processes#
What are the characteristics of a high energy coastline?
- Destructive waves
- Higher rates of erosion than depsition
- Steep cliffs
- Created by exposure to long fetches and strong winds.
- Has rocky landforms
What are the characteristics of a low energy coastline?
- Constructive waves
- Created by gentle winds and short fetches and a sheltered location.
- Higher rates of deposition than erosion.
- sandy beaches, esturaries, mud flats
- sediment is supplied from terestrial and offshore sources.
What is a discordant coastline?
Where the bands of alternating hard and soft rock are at right angles to the coast.
How are headlands and bays created?
Less resistant rock is eroded faster forming a bay. More resistant rock is eroded less quickly so sticks out as a headland.
What is a concordant coastline?
The bands of rock run paralell to the shoreline.
How is a cove formed?
Once waves break through the more resistant outer rock, it exposes the less resistant rock. Waves erode the softer rock at the faster rate until it hits the harder rock behind it.
