lesson 6/7- coastal erosion + landforms Flashcards
what is a wave cut notch
small indent at the base of a cliff formed when a cliff is undercut by the sea
-wave quarrying
what is a wave cut platform
coastal benches- narrow flat area found at the base of a sea cliff or on the shore than was created by coastal erosion
what is a geo
long, narrow, steep sided cleft formed by erosion in coastal cliffs
what is a blowhole
formed as sea caves grow landwards and expose themselves towards the surface
-can result in blasts of water if conditions are appropriate
what is a swash aligned beach
parallel to incoming wave crests
-minimal long shore drift
what are drift aligned beaches
parallel to the dominant direction of longshore drift
what is a spit
deposition bar or beaches landform
-develops in places where re entrance occurs, by process of longshore drift
what are sand dunes
a ridge of sand created by the wind
what is a salt marsh
an area of coastal grassland that is regularly flooded by seawater
-spits provide shelter to areas. Low energy gentle waves enter the area and deposit find material
-these build up and are colonised by vegetation
what is a tombolo
a bar of sand or shingle joining an island to the mainland
-if there is no strong current, wave refraction will result in slower waves, bending them to deposit material
what is a bar
what is a offshore bar
a shallow area of sand or mud, usually deposited near a mouth
elongate ridges deposited beyond a shoreline by currents and waves
what is a barrier beach/island
a sand or shingle bar above high tide, parallel to coastline and separated from it by a lagoon
what is a psammosere
an ecological succession that began life on newly exposed coastal sand
-mostly sand dune systems
what is a embryo dune
wind deposited sand on and leeward of obstructions
what is a foredune
a part of a system of dunes on the side nearest to the sea
what is a mobile dune
upward growth of the embryo dunes allows the surface to be raised so it is out of reach of most tides
this results in a less salty and unstable substrate
what is a fixed dune
when vegetation has developed so it covers the substrate, ‘fixed’
what is a dune slack
low-lying areas within dune systems that are seasonally flooded and where nutrient levels are low
what is a wasting dune
very little sand accumulates beyond grey dunes and dune ridges
-> wasting dunes
what is a yellow dune
develop after the first set of embryo dunes appear
what is a grey dune
fixed, stable sand dunes that are covered by vegetation
found on the landward side of foredunes
what is a dune heath
without a large plant biomass, plant nutrients are leached out the soil surface -> dry, acidic and nutrient dead area
-plants are adapted to this
what is a blowout
sandy depressions in a pasammosere caused by the removal of sediment by wind
-patches of bare sand on stabilised vegetative dunes
what is the formation of sand dunes
sand becomes trapped by obstacle.
-first dunes to develop are called embryo dunes
-grow up and stabilise
-long roots and shoots of marram grass bind the soil
-continued growth makes the dunes out of reach to most tides (foredunes)
-these mobile dunes are initially yellow
-as vegetation cover increases, they become grey
-fixed dunes
-behind the yellow and grey dunes, limited supply of sand so dunes in this area are called wasting dunes
