coasts EQ1 Flashcards
what is the littoral zone?
the boundary between land and sea. A constantly changing zone because of the interaction between the processes operating in the seas, oceans, and on land.
what are the sections of the littoral zone?
backshore (above influence of waves)
foreshore (inter-tidal surf zone)
nearshore (breaker zone)
offshore (beyond influence of waves)
what is dynamic equilibrium?
when inputs and outputs of the open coastal system are balanced and equal
what are the inputs of the coastal system?
marine: waves, tides, storm surges, salt spray
atmospheric: wind, climate, solar energy
land: geology, lithology, tectonic
people: management, urbanisation
what are the processes of the coastal system?
erosion
deposition
transportation
weathering
mass movement
what are the outputs of the coastal system?
erosional landforms: headlands, bays, caves, arches, stumps, stacks, wave cut platforms
depositional landforms: spits, salt marshes, beaches, sand dunes
discordant/ concordant coasts
define geology
an earth science comprising the study of solid earth, the rocks of which it is composed, and the processes by which they change
what is igneous rock
formed through the cooling and solidification of magma or lava e.g. pumice
what is a sedimentary rock?
formed by the accumulation and the consolidation of sediments e.g. limestone
what is metamorphic rock?
a result of a transformation of a pre-existing rock. The original rock is subjected to high heat and pressure, which cause physical and chemical changes e.g Marble
what is a high energy coastline?
Rocky coasts, in the UK, these tend to be stretched on the Atlantic facing coast, waves here are powerful for most of the year e.g. in Cornwall. Rate of erosion exceeds rate of deposition. Erosional landforms such as headlands, cliffs, and shoreline platforms are found here.
what is a low energy coastline?
sandy and estuarine coasts, in the UK these tend to be stretches of the coast where the waves are less powerful, or where the coast is sheltered from large waves. In these areas, the rate of deposition exceeds the rate of erosion. Landforms such as beaches, spits, and coastal plains tend to be found here
what are some features of high energy coasts?
destructive waves, stormy conditions, erosion, long fetches, rocky landscapes, atlantic coasts, cliffs, wave cut platforms
what are some features of low energy coasts?
constructive waves, deposition, beaches, spits, lowlands, east anglian coasts
define lithology?
the rock type. The physical and chemical characteristics of rocks in a particular location. Lithology is small scale- seen under a microscope or in a rock specimen
explain weak and strong lithologies
weak: low resistance to erosion, weathering, and mass movements
strong: highly resistant to erosion, weathering, mass movements
where in the UK is more resistant geology?
south west of the UK bears the brunt of the worst of the weather from the Atlantic ocean. Cornwall’s rocky coastline can withstand the frequent winter storms without suffering from rapid erosion- it is made from older and more resistant rocks such as igneous rocks, older compacted sedimentary rocks, and metamorphic rocks.
where in the UK are coastal plain landscapes?
east and south of the UK -weaker younger rocks including chalk, clay, sand, and sandstone. Environments are low-energy so wave power isn’t as strong- more deposition happening than erosion. If wave power was much stronger, erosion would be vast. The wash is an area of low, flat relief referred to as a coastal plain. It has a range of habitats from tidal creeks to mud flats, salt marshes and lagoons. Much of the eastern coast consists of low-lying sandy beaches, for example, Bamburgh beach in Northumberland
define coastal morphology
the shape and form of coastal landscapes and their features
define coastal recession
the retreatment of the coastline inland due to erosion
define strata
layers of rock
define bedding planes
horizontal cracks, natural breaks in the strata, caused by gaps in time during periods of rock formation
define joints
fractures caused either by contraction as sediments dry out, or by earth movements during uplift
define folds
formed by pressure during tectonic activity, which makes rocks buckle and crumple