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LANDSCAPE CHANGES - TIME SCALES 1.1.8 - Coggle Diagram
LANDSCAPE CHANGES - TIME SCALES
1.1.8
RAPID CHANGES - CLIFFS
high energy/storm events
rapid mass movement
sudden change to cliffs
example: FAIRLIGHT, ENGLAND
slumping - clay cliffs - heavy rainfall and wet winters make it weak
mud flows
undercutting of base by high energy waves
SEASONAL CHANGES - BEACHES
WINTER
major storms
high energy waves
destructive waves
strong backwash
profile = convex, flattened lower section - steep upper
offshore bar
SUMMER
no major storms
low energy waves
constructive waves
builds up beach
gradient increases - low wave steepness
return the lost sediment from winter
LONG TERM, STEADY, EQUILIBRIUM
MILLENNIA
EUSTATIC
affects WHOLE WORLD
sea level changes
alteration in volume of water
during and after ice age - temperature decreased, water froze, suspended hydrological cycle, decreased sea levels
after ice age - increased temperature, ice melts, increased sea level
tectonic change
ISOSTATIC
increase or decrease in height of land
ice age - ice = heavy, increased weight of land, land sinks, higher sea level (compression)
ISOSTATIC REBOUND - ice melts, decreased weight of land, land rises, lower sea level
tectonic uplift
LOCAL
EMERGENT LANDFORMS
end of ice age - isostatic rebound - faster than eustatic rise
raised beaches, arches, caves, stacks - degraded form
example: RHOSSILI BEACH, SWANSEA
sub-aerial processes become more infuencial
SUBMERGENT LANDFORMS
eustatic rise = faster than isostatic rebound
water floods land - fills up landforms
RIA
floodplains and valleys are flooded - estuary
FJORD
flooding of glaciated U-shaped valley
important routes for water traffic - ferries
very deep and wide