Why are coastal landscapes different and what processes cause these differences? Flashcards
What is the littoral zone?
The boundary between land and sea which stretches out into the sea and onto the shore
What are the sub zones of the littoral zone?
coast backshore foreshore nearshore offshore
Two main types of coasts
- rocky (or cliffed) coastlines with cliffs varying in height from a few meters to hundreds of meters
- coastal plains (with no cliffs) where the land gently slopes towards the sea across an area of deposited sediment, often in the form of sand dunes and mud flats
primary coasts
dominated by land- based processes, such as deposition at the coast from rivers or new coastal land formed from lava flows
secondary coasts
dominated by marine erosion or deposition processes
emergent coasts
where the coast is rising relative to sea level, for example as a result of tectonic uplift
submergent coasts
are being flooded by the sea either because of sea level rise and/ or subsiding land
low wave energy
sheltered coasts with limited fetch and low wind speeds resulting in small waves
high energy waves
exposed coasts with limited fetch and low wind speeds resulting in small waves
what are subaerial processes?
the processes of weathering and mass movement
long and short term ways to classify coasts
long term
- geology
- sea level rise/ change
short term
- wave energy
- wave type
describe the geology across the UK
- eastern and southern coasts consist of weaker and younger sedimentary rock e.g chalk
mud flats, beaches etc - above the tees and exe line is harder igneous and metamorphic rock
cliffs and rough landscapes
What is accretion?
it refers to the deposition of sediment at a coast that expands the area of land
strata
the different layers of rock exposed in a cliff
deformation
tilting and folding by tectonic activity
faulting
major fractures that have moved rocks from their original positions
concordant/ pacific coasts
when rock strata run parallel to the coastline
discordant/ atlantic coasts
when different rock strata intersect the coast at an angle, so rock varies along the coastline
what is a dip?
this refers to the angle at each rock strata lie
joints
(vertical cracks) fractures caused either by contraction as sediments dry out, or by earth movements during uplift
example of concordant coastline
Lulworth cove
Dalmatian coastline
- concordant coastline
- formed as a result of a rise in sea level
- when the valleys flooded because of this rise, the tops of the ridges remained above the surface of the sea - as a series of offshore islands that run parallel to the coast
e. g Croatia
Haff coastlines
- concordant coastline
- long spits of sand and lagoons aligned parallel to the coast
e. g southern shore of the Basaltic sea - lagoons enclosed by sand spits or dunes
examples of sedimentary rock
sandstone
limestone
shale
examples of igneous rock
granite
basalt
dolerite
examples of metamorphic rock
slate
schist
marble