Quick revision Flashcards
What are the 2 types of currents?
rip currents
upwelling
what are rip currents
strong currents which flow away from the shoreline
What is upwelling
the movement of cold water form the deep ocean to the surface
How many high and low tides a day
2 of each a day
How many neap and spring tides a month?
2 of each a month
What other elements can affect tides
shape of seabed, coriolis effect
What is tidal range
difference in hight between high and low tide
What causes storm surges?
due to low-pressure created by atmospheric depressions
What is cavitation?
form of erosion where air bubbles trapped in water are compressed into small pieces
What happens during cavitation?
waves hit cliff and air bubbled forced into cracks in rock face pressure compresses air bubbles forcing them into solution. As waves retreats, pressure is reduced and air comes out of solution, causing micro-detentions, enlarges crack
What is carbonation?
type of chemical weathering that takes place when its warm and wet
How does carbonation work?
CO2 dissolves in rain making it a weak carbonic acid.The acidic rain water dissolves types of rock that contain calcium carbonate
What is salt weathering
main type of mechanical weathering where salt water gets into cracks in rock, salt crystals form when seawater evaporates, crystals expand and put pressure on the rocks
How many sediment cells are there in the uk
11
What is a discordant coast line
Alternating bands of soft and hard 90* to the coast
What is a concordant coastline
alternating bands of soft and hard rock parallel to coast
What is a Dalmatian coast
made up of offshore islands running parallel to coastline
What kind of waves are responsible for the formation of wave-cut notch
destructive waves hitting the bottom of the cliff
Describe the different dunes
mobile dune near water (embryo,fore,yellow) and fixed dunes further back (grey dunes and dune slacks)
What type of vegetation is found in embryo and foredunes
sea rocket- have deep roots that can tolerate high concentrations of salt
What type of vegetation is found in yellow dunes
marram grass-long, deep roots are sea tolerant
What type of vegetation is found in grey dunes
heathers, bc of higher rates of humus
What is flocculation?
process where fine particles clump together
How does a mudflat become a salt marsh
through succession when pioneer species roots stabilise mud, build up leading to creeks and rivers,rises above sea level
What causes emergent coastlines?
isostatic rebound
What features do emergent coastlines form
raised beaches, fossil cliffs
What featured do a submergent coastline form
rias, fjord, Dalmatian coasts
What is a ria?
flooded river valley
What is a fjord
flooded glacial valley, creating u-shaped valley
What is strata
different characteristics of rock
What happens at steeper coasts in terms of erosion
more erosion bc more water directed to land
Some rock type factors that effect landslips and slumping
-Competent or uncompetent rock
-Porosity or permeability
-angle of bedding planes
-if ground is wet
What happens at competent rocks
slipping
What happens at uncompetent rocks?
slumping
What is needed to create an offshore bar
low energy environment
How is an offshore bar formed
sand taken off beach, when water deep enough , drops sediment where still zone starts
What are the 2 kinds of spits
simple and compound
