[Unit 2B: Enquiry Question 1] Flashcards
Coastal Landscapes
define “littoral zone”
wider coastal zone, including: adjacent land and shallow parts of sea
what features are there in the backshore
beaches, dunes, cliffs
what processes are there in the backshore
atmospheric.
erosion.
human activity.
deposition
transportation
what features are there in the foreshore
inter-tidal zone
sand ridges
what processes are there in the foreshore
Marine:
-wave
-tides
-storm surges
Atmospheric:
-sub aerial
what features are there in the nearshore
longshore bars
sand
what processes are there in the nearshore
Marine:
-waves (break)
-tides
-storm surges
what features are there in the offshore
offshore sands
what processes are there in the offshore
Marine:
-tides
What are 6 (of many) ways of classifying coasts
Geology
Energy
Balance (between erosion and deposition)
Sea level
Formation processes
Tidal range
what type of: waves, processes, land forms and general location. is at low energy coasts
less powerful waves
deposition and transport
Beaches, salt marshes, sand dunes
sheltered, lowland, coastal plains
Med sea coasts
what type of: waves, processes, land forms and general location. is at high energy coasts
more powerful waves
erosion and transport
cliffs, arches, caves, stacks
exposed, highland&lowland, rocky coasts
Atlantic coasts of Norway and Scotland
define “discordant coastline”
bands of differing rock type run perpendicular to the coast
define “concordant coastline”
bands of differing rock type run parallel to the coast
what features are formed at a discordant coastline
bay and headlands
ensure you know how they are formed
what is wave refraction
energy from waves is focused on the headlands as it sticks out
bay is sheltered
headland erodes and sediment is deposited on the beach
how do coves form
hard rock is breached allowing the sea to the soft rock
the soft rock erodes quickly forming a cove
what are some concordant coastline features
dalmatian coastline
haff coastline
cove
what is a dalmatian coastline
valleys/ridges run parallel to each other
valleys/ridges flood due to sea level rise
tops of valleys/ridges remain above sea
they become offshore islands parallel to coast
what is an example of a dalmatian coastline
Dalmatia coast in Croatia
what is a Haff coastline
formed in low energy environments
where deposition of mud and sand
long ridges topped with sand dunes
are parallel to coast
creates lagoons between ridge and coast
what is a “dip”
variation in angle of rock strata
how do “dips” form
tectonic forces deform rock layers
-through compressional & tensional forces
high heat & pressure causes rock to bend & break
this causes the variation in angle of rock strata
what is an example of a dip
Stair Hole in Lulworth
define “strata”
layers of rock
define “bedding plane”
breaks in strata from gaps in time during rock formation. creates horizontal cracks
define “folds”
pressure during tectonic activity makes rocks buckle & crumple
define “joints”
fractures caused by contraction (as sediments dry out). creates vertical cracks
define “faults”
when stress or pressure exceeds a rocks internal strength. It slips or moves along the plane
a coastline with uniform horizontal strata produces what
steep cliffs
a coastline with near vertical joints produces what
rocks dipping gently seawards that will break off eventually
a coastline with near strata dipping inland produces what
a stable, steep cliff profile
how are igneous rocks formed
cooling and solidification of magma
how fast and why do igneous rocks erode
very slow. Few joints, interlocking crystals so limited weaknesses that erosion can exploit
how are metamorphic rocks formed
original rock subjected to heat/pressure causing physical/chemical changes
how fast and why do metamorphic rocks erode
slow. heavily fractured, if all crystals orientate in one direction causes weaknesses for erosion
how are sedimentary rocks formed
cementation of minerals or organic particles
how fast and why do sedimentary rocks erode
moderate/fast. many bedding planes and fractures so vulnerable to erosion
what two factors affect a cliff profile
strata permeability
strata resistance
what feature forms from a difference in permeability in a cliff
slumps
surface run off erosion from ground water emerging
define “unconsolidated”
sediment which is not compacted together
what three coast lines are formed from vegetation succession
coastal sand dunes
coastal salt marshes
coastal mangrove swamps
define “halophytes”
plants that tolerate salt water
define “xerophytes”
plants that tolerate very dry conditions
how does vegetation succession take place in sand dunes
-pioneer colonise sand, roots bind sand
-pioneer die and decompose. form thin soil (very alkaline)
-soil deepens and less alkaline from more organic matter. small plants and larger plants
-soil deepens, small trees move in out competing smaller plants
-soil supports large trees. fast growing then slow growing
what is the order of sand dunes from youngest to oldest
“berm”
embryo
fore
yellow
grey
mature
how do sand dunes form
deposition from long shore drift
winds pick up sediment and blow inland
sand trapped and slowed by obstacles
starts piling up
what is the process of salt marsh succession
algae grows, roots bind mud
cord grass roots stabilise mud
marsh grass creates carpet so height increases
scurvy grass prevents salt getting under marsh
sedge grass grows as marsh is only submerged once or twice a year
how do salt marshes form
in low energy environment
deposition/long shore drift and silt from river is deposited on side of estuary
pioneer plants survive
trap more sediment
make it higher
more plants can grow
give an example of a salt marsh in the UK
Keyhaven Salt Marsh, Hampshire
give an example of sand dunes in the UK
Studland sand dunes, Dorset
