EQ1 2B.1 Flashcards
(10 cards)
What is the littoral zone? + describe it
Area of coast subject to wave action
Offshore - deep water beyond influence of waves (open sea)
Nearshore - shallow water beyond the low tide mark, breaker zone
Foreshore - inter-tidal zone where most wave processes occur
Backshore - above high tide level, only influenced by major storm events
Why does the littoral zone constantly change?
ST factors - tides, storm surges
LT factors - changes is sea level, climate change
What types of coastal landscapes does the littoral zone form
Rocky, cliffed coastline
Sandy coastline
Estuarine coastline
What causes rocky coasts?
Usually high relief
Resistant geology
High energy environment - more powerful waves, large fetch, destructive waves
Erosion>deposition
What causes sandy coasts?
Low relief
Less resistant geology
Low energy, sheltered environment - less powerful waves, constructive waves
Deposition>erosion
What causes an estuarine coastline?
Low relief - w salt marshes + mudflats, form in river mouths
Less resistant rock
Low energy environment
Deposition>erosion
How can coasts be classified using LT criteria
Geology
-lithology: rock type
-structure: arrangement of rock
-can be used to classify coasts as rocky, sandy, estaurine OR concordant, discordant
Sea Level Change
-tectonic processes can uplift land causing local sea fall/cause subsidence causing local sea rise
-Climate change causes SL rise in interglacial periods (periodic change in Earth’s orbit)
-used to classify as emergent/submergent
How can coasts be classified using ST criteria
Energy inputs
-classify is high/low energy
Sediment inputs
-classify as advancing/retreating?
What is accretion?
Continuous accumulation of sediment
Where does sediment come from in coastal plains
Offshore sources transported by waves, tides, currents
Terrestrial sources transported by rivers, glaciers, wind, mass movement
