Coasts Flashcards

Question

Highest low tides and lowest high tides

Answer 1

. when the sun and the moon are perpendicular to each other so gravitational forces work against each other -neap tides

Answer 2

The seasonal movement of water in the seas and oceans

Answer 3

. Strong steady prevailing winds, creating high energy waves . Rate of erosion> Tate of deposition . Typical landforms: headlands, cliffs and wave cut platforms . Eg north Cornish coast

Answer 4

. Coastlines where wave energy is low . Rate of deposition > Rate of erosion . Typical landforms: beaches and spits . Eg the Baltic Sea

Answer 5

Is the area lying between the high water mark and the landward limit of marine activity

Answer 6

Area lying between high water mark and low water mark

Answer 7

Area between the low water mark and the point where waves have no influence on the land beneath them

Answer 8

Area beyond the the point where waves impact the sea bed

Answer 9

. Waves refract onto the headland . The waves become higher, steeper with shorter wave length . High energy waves concentrated on the headland, increasing erosion . Waves refract out onto bay . Waves in the deep water are still moving forward so the waves bend . Low energy waves concentrated in the bays, increasing deposition

Answer 10

. Prevailing wind approaching the beach at an angle . Sediment is dropped back out to sea . Picked up by the prevailing wind and pushed back up the beach before it’s then dragged back out to sea

Answer 11

. Strong currents moving away from the shoreline . Sea water is piled along the coastline by incoming waves . Current runs parallel to coast before flowing to breaker zone, at a headland

Answer 12

. Weathering . Mass movement

Answer 13

. Erosion . Deposition . Transportation

Answer 14

. Longshore drift deposits sand and shingle across the river mouth, leaving a bank of sand and shingle sticking out to sea ( a straight spit that grows out roughly parallel to the coast is called a simple spit )

Answer 15

. Changes in wind direction lead to curved end . This can happen multiple times creating multiple recurved ends

Answer 16

Formed where a spit grows across a bay. Behind the bar forms a lagoon where water is trapped. Over time the lagoon will be filled up with Silt and may gradually form salt marshes

Answer 17

. Found at the edge if the permanently submerged marine zones

Answer 18

When sea level itself rises or falls (global)

Answer 19

When land rises or falls relative to the sea (local )

Answer 20

. An increase in temperature causing melting ice sheets, which increases sea level . A decrease in temperature causing more precipitation to fall as snow. This increases the volume of water stores in glaciers and so reduces the volume of the sea, decreasing sea level . Changes in earth’s tectonic movement alters the earths shape and volume of ocean basin e.g sea floor spreading increases the volume of basin so decreases sea level

Answer 21

. Slow uplift of land can continue for thousands of years after the weight of retreating glacier has gone . Subsidence of land due to shrinkage after abstraction of ground water e.g drainage of marshland . tectonic crustal processes: one plate is forced beneath another at a plate margin

Answer 22

Stretches along the coast have been inundated by the sea due to eustatic changes

Answer 23

Stretches along the coast have been exposed by the sea due to Isostatic changes

Answer 24

. Rias . Fjords . Dalmatian coastlines

Answer 25

. Raised beaches . Marine platforms

Answer 26

. Shifting material downhill due to gravity . In coastal areas, cliffs are undercut by wave action which causes an unsupported overhang and collapses . Slides- material shifts in a straight line . Slumping- material shifts with rotation . Unconsolidated rocks are prone to collapse as there is little friction . Runoff can erode fine particles and transport them downslope

Answer 27

. Water gets trapped in rocks, increasing water pressure which forces rock particles apart and leads to slope failure . Unconsolidated rock is prone to collapse due to little friction . Heavy rainfall can saturate Unconsolidated rock, further reducing friction and making it more likely to collapse . Runoff can erode fine particles and transport them downslope

Answer 28

Freeze thaw- .water enters cracks in the rocks which the freezes (temp below 0 degrees) . the water expands by almost 10% meaning ice occupies more space and so exerts pressure surrounding the rock . As process repeats, the crack widens, breaking the rock

Answer 29

breakdown of rocks by the Action of vegetation and coastal organisms . marine organism such as piddocks (a shell fish ), have specifically adapted shells that enable them to drill into solid rock

Answer 30

Carbonation . When carbon dioxide dissolves in rainwater makes a weak carbonic acid. This reaction with calcium carbonate in rocks like limestone and chalk creates calcium b carbonate, which dissolves easily in water

Answer 31

Area of land between the cliffs or dunes and offshore area beyond the limit of the waves

Answer 32

. Winds move across surface of the water Causing frictional drag ( ripples and waves are created) . the sea bed becomes shallower towards the coastline and orbit of water particles becomes more elliptical, leading to horizontal movement of the waves . The wave height increases but the wave length and wave velocity decreases . This causes water to back up behind the wave until wave breaks and surges up the beach

Answer 33

. Strength of wind- the larger the pressure between two areas, the stronger the wind . Duration of wind- if wind is active for longer periods of time, then the energy of the waves build up and increase .Size of Fetch- the larger the distance over the wind blows the more powerful the waves will be

Answer 34

. Constructive waves dominate but destructive waves dominate in winter . Constructive waves may become destructive waves if a storm begins . Climate change may increase storm frequency within the UK . Coastal management may affect the type of waves that occur

Answer 35

. constructive waves causes deposition on the beach, which leads to the beach profile becoming steeper . Steeper beaches favour the formation of destructive waves, which are then more likely to occur . Destructive waves erode the beach, reducing the beach profile and leading to the formation of constructive waves . Constructive waves occur more frequently in the summer, meaning that beach profile is more gentle and steeper durning the winter where destructive waves are more common

Answer 36

. Due to different rock strengths, erosion leads to the formation of headlands, where resistant rock exists and bays where unconsolidated rocks and clays are dominant . This increases the forces of erosion in headlands and reduced erosion in bays. . Headlands are worn away which again increases erosion within the bays

Answer 37

When breaking waves hit the cliff face to directly pull away rocks or remove smaller weathered fragments

Answer 38

. Waves . Beach size . Activity of sub aerial processes

Answer 39

. Coast effective - P . Rocks are sourced from elsewhere so do not fit with the local geology- N . A hazard if climbed upon- N

Answer 40

. Created and important wild life habitat- P . Farmers lose land and may need to compensate as a result- N

Answer 41

. Effective erosion prevention- P . Promenades has tourism benefits-P . Visually unappealing- N . Expensive to construct

Answer 42

. ICZM recognises that coastal management must be sustainable . Involves all stakeholders and plans for the long term . In 2013, the EU adopted a new initiative which promotes the use of ICZM

Answer 43

. Hold the line- defences used to maintain the current position of the shoreline . Managed retreat- engineering techniques are used to allow the coastline to advance inland and create its own natural defences . Advance the line- defence are built to try and move the shoreline seawards . No active intervention- the shoreline is exposed to natural processes

Answer 44

When rising sea levels flood narrow inlets and river valleys. They are deeper at the mouth of the inlet, with the water depth decreasing further inland

Answer 45

when rising sea levels flood deep glacial valleys to create natural inlets and harbours eg in New Zealand very straight and narrow and has very steep sides

Answer 46

when valleys running parallel to the coast become flooded as a result of sea level changes, eg Croatia

Answer 47

Determining spatial limits and the length of time the littoral zone is exposed to sub aerial weathering

Answer 48

. Sea erodes the land so cliff retreats due to action of waves and weathering . This forms a wave cut notch at the high water mark which eventually develops into a cave . Rock above becomes unstable and collapses . Wave cut platform is formed

Answer 49

. Bands of hard rock and soft rock at right angles to the shoreline . Soft rock erodes quickly forming a bay, the hard rock erodes slowly and sticks out as a headland.

Answer 50

. Spits are formed when the coast suddenly changes direction . Longshore drift continues to deposit material across the river mouth leaving a bank of sand and shingle . A straight spit that grows parallel to the coast is called a simple spit . Changes in dominant wind and wave direction may lead to spit having curved end ( recurved end). Over time this can create compound spits . The area behind this develops into mudflats and saltmarshes

Answer 51

. Spit joins two headlands together and a bar is formed . A lagoon forms behind the bar . Some bars form off the coast when material moves towards the coast( at sea level rise)- offshore bars . Bar connects the shore to an island is called tombolo e.g St Ninian’s Isle

Answer 52

. Sand deposited by littoral drift . Sand trapped by berms is colonised by plants and grasses. . The vegetation stabilises the sand and encourages more sand to accumulate forming embryo dunes . Over time, older dunes move inland- mature dunes can reach 10m in height

Answer 53

. Silt and mud are deposited by the river tide- mudflats develop . Mudflats colonised by vegetation that survived high salt levels and long periods of submergence by tides . Plants trap mud and silt creating exposed salt marshes between tides

Answer 54

. Sand runs parallel to the shore that is detached. . Form in areas with large amount of sediment, gentle slopes offshore, powerful waves and small tidal ranges . Not clear how it is formed but scientists say it was formed after last ice age which caused rapid sea level rise. . Another theory is that islands where originally bars attached to the coast which is eroded into sections causing beaches. . Lagoon formed behind barrier island eg in Horn Island in Mississippi, east coast of USA

Answer 55

. the fall of sea level leaves beaches above high tide mark . sea level fall exposes wavecut platforms, leaving them raised above their former level . The cliffs above the raised beaches are no longer eroded by the sea, so they are slowly covered by vegetation ( relict cliffs) . these raised features are degraded overtime

Answer 56

. around 20,000 years ago, sea levels have been rising .sea levels have increased in about 235mm

Coasts Flashcards

(80 cards)