coasts glossary

abrasion

a form of erosion where loose materials erodes the walls and floors of the cliff/river, via a ‘sandpapering’ effect

backshore

the upper beach, furthest inland - includes cliffs and sand dunes

bar

a section of sand caused via deposition - they join two sides of a bay together, creating a lagoon

beach morphology

the surface shape of the beach

beach nourishment

the addition of sand/sediment to an eroding beach by humans

• this new material will eventually be eroded, instead of the cliffs or dunes from erosion/recession

coastal recession

where a coastline retreats due to erosion, sea-level rise or submergence

concordant coast

a coastline where bands of alternating geology run parallel to the coast

discordant coast

a coastline where there are perpendicular bands of alternating geology to the coast

corrasion

a form of mechanical erosion

where loose material and sediment from the sea is flung at a the cliff face as waves break, causing erosion (and therefore weakening)

dalmatian coast

a concordant coastline with several river valleys running perpendicular to the coast.

the valleys then flood due to sea levels rising and produce long islands and inlets

dynamic equilibrium

a system where inputs and outputs are in balance with one another - short term changes can then affect this balance

• negative feedback loops can then help restore dynamic equilibrium

emergent coast

a coastline that is advancing relative to the sea level at the time

estuary

the point at where the river meets an ocean - often muddy or silty.

• often become exposed at low tide

eustatic

global changes to sea level

fetch

the distance that the wind has travelled over the water

fjord

a long, narrow inlet of water between steep mountains

• fjords are formed when the sea level rises relative to the land, causing coastal glacial valleys to be flooded

foreshore

the lower part of the beach covered twice a day at high tide (receives most regular wave action)

grading

the layering of sediments based on size

glacial erosion

plucking, abrasion, crushing and basal meltwater

groyne

form of hard engineering; low-lying concrete or wooden walls, constructed perpendicular to the seafront, running out to sea

• they encourage sediment to be trapped, slowing and discouraging erosion via longshore drift or winds

hard management

the use of concrete structures to reduce/halt coastline recession

• groynes, sea walls and rock armour

high-energy environment

a coast where wave action is predominantly made by destructive waves, causing a lot of erosion

low-energy environment

where wave action is predominantly small, constructive waves, allowing deposition to take place

beach accretion

where beach sediment returns to the visible beach, helping to restore or extend the coastline

hydraulic action

where the pressure of compressed air forced into cracks in a rock face causes the rock to weaken and break apart

ICZM

integrated coastal zone management

• where large sections of coastline are managed with one integrated strategy and management occurs between different political boundaries

impermeable

a rock that does not allow water to pass through it

permeable

rock that does allow water to pass through it

isostatic

a local change in sea level due to change in local coastline/height of land

littoral cell

an area of coastline which has all sediment processes occurring (sources, transports and sinks)

• not a closed system

longshore drift

the transportation of sediment along a beach (usually determined by direction of prevailing wind)

mass movement

where there is a large downhill movement, usually from a cliff face

• usually occurs where that rock is weak due to erosion, and gravity causes the movement

nearshore

the area before the shore where the wave steepness breaks before they reach the shore. extends from low tide zone, out to the sea