OFFICE 365 REVISION PACK Q's Flashcards
Describe essential features of the back shore (3 marks)
The part of beach lying between foreshore & coastline. The back shore is dry under normal conditions, is often characterised by berms and is without vegetation.
Backshore is only exposed to waves under extreme events with high tide and storm sugres.
What are the essential features of the nearshore? (3 marks)
Underwater area close to the beach, often characterised by sand bars, where sediment is actively being moved by waves and currents
What are sub-aerial processes? (3 marks)
Combination of weathering and mass movement
•Mechanical/physical weathering is the fracture and breakdown of rocks into fragments
•Along the coast it may be caused by frost shattering (freeze-thaw), salt crystallisation, wetting & drying.
What are the essential features of coastal plains? (3 marks)
A coastal plain is flat, low-lying piece of land next to the ocean. Coastal plains are separated from the rest of the interior by nearby landforms, such as mountains. Coastal plains can form in two basic ways: some start as a continental shelf, a flat piece of land located below sea level. When sea level falls, land is exposed, creating coastal plain.
What’s the difference between concordant and discordant? (4 marks)
DISCORDANT: rocks run perpendicular (right angles) to coastline
CONCORDANT: Rocks run parallel, creating a protective barrier
What are the influences of dip on cliff profiles? (6 marks)
Rocks tend to form in layers of different rock types known as beds. These beds are subjected to tectonic forces that tilt and deform them, do they dip at an angle.
•Beds that are seaward produce gentler cliffs that are less stable because loose material can slide
•Landward dipping beds produce stable and steeper cliffs
What is the formation of salt marshes? (4 marks)
Usually in areas that are well sheltered where fine sediments can be deposited.
Also form behind spits and sea defences where tidal waters flow gently
•Salt marshes are exposed at low tide and at least partially flooded at high tide.
Why is marram grass so important?
Marram builds dune higher as it anchors sand down
•When it dies, it leaves behind rich nutrients to help the next stage of vegetation grow
Difference between tides & currents? (4 marks)
TIDES: Driven by gravitational force of moon and sun. Characterised by water moving up and down over long period.
•Oceanic currents are driven by the rise and fall of tides
•Tides create current in the oceans
What are sediment cells? (4 marks)
Considered a closed coastal sub-system
•They are determined by the topography and shape of coastline which directs the movement of sediment within the cell
•Sediment is largely recycled within them rather than having significant new inputs or outputs.
Difference between Eustatic and Isostatic sea level change? (4 marks)
EUSTATIC=
Sea level changes due to alteration of volume of water in oceans or a change in shape of an ocean basin
ISOSTATIC=
Result of an increase/decrease in height of land. When height of land increase, sea level falls and when height of land decreases the sea level rises.
What are some coastal features created by a rising sea level? (4 marks)
SUBMERGING= Ria, which is a river valley that’s been flooded by Eustatic rise in sea level.
-Fjord=Steeper and deeper variants of raises they are relatively narrow for their size. They have U-shaped cross profile.
•Dalmatian coastlines= form in areas where valleys lie parallel to each other. When the valleys are flooded by the rise in sea level, the tops of the valleys remain above the surface of the sea and appear to be a series of islands that run parallel to coastline.
Factors which encourage coastal recession? (4 marks)
Type of wave: constructive vs destructive
Type of rock: hard or soft rock
How the rock runs to coastline: CONCORDANT = parallel to coast or DISCORDANT = right angles, meaning more erosion
How is modern technology helping to measure coastal recession? (4 marks)
Shoreline mapping
Beach profiling surveys
Analysing historical maps
What is a storm surge? (3 marks)
Large scale increase in sea level due to a storm. Low atmospheric pressure allows sea level to rise, and gale force winds combined with the Earth’s rotation forces water towards the coastline.
