Coasts EQ1 Flashcards
What is the littoral zone?
The wider coastal zone including adjacent land areas.
Think of it as a cross section
What are the subdivisions in the littoral zone?
Offshore, Nearshore, Foreshore, Backshore and Coast/Land
Describe some contrasting coastlines
Rocky Coastline (HIGH cliff) - low tide - bottom of cliff exposed - resistant geology - HANGMAN CLIFFS DEVON
Sandy Coastline - Dunes - Low energy and deposition. DORSET SAND DUNES
Estuarine coastline - Found at river mouths, gradual transition from land to sea - LYMINGTON
What is an emergent coastline?
Land is rising relative to sea levels.
What is the 5 criterea used to classify a coast
- Geology - Rocky or sandy coastlines / concordant or discordant coastlines.
- Wave energy - High or Low energy enviroments
- Relative sea level change - create either emergent or submergent coastlines.
- Formation processes - primary or secondary coastlines
- Tidal range
What is a submergent coastline?
Where sea levels are rising relative to the land / land is sinking.
Cornwall
What is deformation
Deformation 🔄 – When rocks bend or change shape due to pressure from tectonic activity.
Describe a high energy coastline
High-Energy Coasts 🌊⚡ Powerful & Erosive
Strong waves, heavy erosion
Found on open coastlines
Rocky cliffs, pebbles, and few sediments
Erosion & transportation
Cliffs - Wave Cut platforms- Sea caves - CASS
Describe a low energy coastline?
Low-Energy Coasts 🌊➡️ Calm & Sheltered
Gentle waves, little erosion
Found in bays, estuaries, and lagoons
Builds up sand and mud (deposition)
LSD & currents
Beaches - spits - sand dunes - salt marshes - bars
What is faulting
Faulting ⚡ – When rocks break and move along a crack (fault) due to stress.
What is “Strata”
Strata 🏔️ – Layers of rock or sediment stacked over time.
What is a concordant coastline?
Bands of hard and soft rock are parallel to the coastline which forms a coast of high cliffs and small caves/coves. Only one type of rock is touching the water unless it gets eroded back into coves. LULWORTH COVE
What is a discordant coastline?
Both hard and soft rock alternate facing the ocean (right angle) - soft rock erodes easy creating bays and headlands.
DORSET.
What is wave refraction (use discordant coast as an example)
This creates wave refraction as headlands absord powerful wave energy and create lower, diverging waves for the softer rock bays. Also water near the headland is shallower so waves slow down and height increases forcing them to crash at headlands.
What is a HAFF coastline
These form where deposition produces unconsolidated geological structures parallel to the coastline. Long sediment ridges run parallel to the coast - just offshore creaing lagoons (haffs) between ridges and shore.
I.E Gdansk Poland Haff coastline.
Concordant
