G2 - coastal landscapes and change 2

?
constructive waves
add sediment onto the beach. strong swash, weak backwash. long wavelength with low height. lead to a steeper beach profile
1 of 18
destructive waves
take sediment away from the beach. weak swash, strong backwash. short wavelength and high height. lead to a flatter beach profile
2 of 18
how waves are formed
created through friction of wind and water, transferring energy and creating ripples that generate into waves.
3 of 18
why do types of waves vary
storms - increase the amount of of destructive waves present. sea level rise - increased volume of water so waves become more destructive. monthly variation - tides controlled by the moon phases. seasonal variation- winter has more destructive waves
4 of 18
how are the erosional processes affected by by wave type, size and lithology
most effective with destructive waves as there is a higher amount of energy present. bigger waves=bigger energy store and hence power. even unconsolidated rock barely erode with constructive waves. faster erosion at high tide- less energy lost
5 of 18
effects of erosion on different coastlines
boulder clay of the Holderness coast has retreated by 120 m in the last 100 years. granite of Land's End in Cornwall has retreated by only 10 cm in the last 100 years.
6 of 18
landforms created by coastal erosion
wave cut notches/platforms-erosion, unstable, collapse. cliffs- rock strata vertical/ horizontal, erosion at the base, maintains profile while retreating.. caves, arches, stacks and stumps- exploit weakness, cave, arch, collapse, stack, stump
7 of 18
types of erosion
hydraulic action (wave energy penetrates). attrition (sediment hits against each other). abrasion (sediment erodes the sea bed/cliffs). solution (dissolving)
8 of 18
types of transport
traction (large particles roll along sea bed). saltation (smaller particles bounce along). suspension (light sediment is carried aloft in the currents). solution (dissolved sediment)
9 of 18
how is sediment transportation influenced by the direction/angle of wave attack
main determinant of direction of transport- wind direction influences swash and backwash and hence the net movement of sediment along a coastline
10 of 18
how is sediment transportation influenced by longshore drift
there is net lateral movement along a coast when waves approach the coast at an angle. on most coastlines there is a dominant prevailing wind, so over time there is a dominant direction of longshore drift.
11 of 18
how is sediment transportation influenced by currents/tides
can transport sediment in the nearshore and offshore zones, can be driven by wind, differences in water density, temperature or salinity. changing tides can create tidal currents
12 of 18
depositional landforms
SPITS. BEACHES. OFFSHORE BARS-sediment eroded by destructive waves, back to sea, deposited. BARS-beach/spit joins 2 headlands-barrier beach/lagoon. TOMBOLO-bar connecting offshore island+mainland. CUSPATE FORELANDS-longshore drift both directions,△
13 of 18
stabilising depositional landforms
sand dunes + salt marshes. vegetation helps to stabilise dunes and salt marshes as a result of plant succession
14 of 18
sediment cells
lengths of coastline that are pretty much self contained for the movement of sediment. closed system with equilibrium inputs/outputs. processes in 1 don't affect processes in another. Englands+Wales coastlines divided into 11 different cells
15 of 18
sediment cell example
-
16 of 18
sub ariel processes
weathering (in situ breakdown of rock-chemical, mechanical, biological). mass movement (movement of weathered material downslope under the influence of gravity- rock fall, slides, slumps mudslides)
17 of 18
landforms created by mass movement
TALUS SCREE SLOPES- debris accumulated from rockfall makes a fan shaped mound of material. ROTATIONAL SCARS - slumping created a curved, unweathered surface on the cliff face. TERRACED CLIFF PROFILES-
18 of 18

Other cards in this set

Card 2

Front

destructive waves

Back

take sediment away from the beach. weak swash, strong backwash. short wavelength and high height. lead to a flatter beach profile

Card 3

Front

how waves are formed

Back

Preview of the front of card 3

Card 4

Front

why do types of waves vary

Back

Preview of the front of card 4

Card 5

Front

how are the erosional processes affected by by wave type, size and lithology

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Geography resources:

See all Geography resources »See all Coastal environments resources »