marine processes L8 Coasts

Question 1

Weathering

Answer 1

the breakdown of rock in situ

Question 2

mass movement

Answer 2

the downhill movement of material under the influence of gravity

Question 3

flows (mass movement)

Answer 3

material is mixed together and is wet, acts like a complete fluid

Question 4

slides (mass movement)

Answer 4

material remains intact and is just lubricated (not necessarily wet)

Question 5

Landslides (mass movement)

Answer 5

flat slide area and tend to be in areas of more resistant geology

Question 6

landslips (mass movement)

Answer 6

areas of weak geology with a curved slide area (rotational slip basically)

Question 7

soil creep vs solifluction (mass movement)

Answer 7

Slow downhill movement of soil
Solifluction is specifically in periglacial environments

Question 8

rockfalls (mass movement)

Answer 8

Collapse of rock fragments in regions of resistant rock

Question 9

slumping

Answer 9

weak geology occurs on a curved surface where saturated soil can undergo liquefaction, (causing rotational slip)

Question 10

Outline the processes of mass movement at the coast.

Answer 10

explain what mass movement is then give examples and explanations of how they work

Question 11

marine process

Answer 11

operates on the coastline and are connected to actions of the sea
E.g. tides and waves

Question 12

sub-aerial processes

Answer 12

operate on land but affect the shape of a coastline
E.g. weathering, mass movement and runoff

Question 13

lithology

Answer 13

geological structure of rock

Question 14

geology

Answer 14

the study of rocks
(Focus on the type of rock)

Question 15

hydraulic action

Answer 15

waves force water into cracks, compressing the air and building up pressure, weakening rock over time

Question 16

cavitation

Answer 16

when bubbles form and collapse violently due to pressure changes, weakening rock (linked to hydraulic action)

Question 17

wave quarrying

Answer 17

energy of waves coupled with hydraulic action breaks away fragments of rock from the coast

Question 18

corrasion

Answer 18

Waves throw sand and pebbles and larger rocks against cliffs, wearing them down like sandpaper

Question 19

abrasion

Answer 19

similar to corrasion, grinding and scraping effect of sediment carried by waves, resulting in smooth cliff faces

Question 20

difference between corrasion and abrasion

Answer 20

corrasion has the erosive impact
Abrasion is the smoothing process

Question 21

solution/corrosion (erosion)

Answer 21

seawater which is acidic due to dissolved CO2, reacts with certain rocks like limestone and chalk, dissolving them over time
Works with carbonation

Question 22

attrition

Answer 22

Rocks and pebbles smash against one another, becoming smaller and rounder, not eroding the coastline but still a process

Question 23

suspension

Answer 23

Finde sediment like sand and silt is carried within the water but not dissolved, making it cloudy

Question 24

traction

Answer 24

Large, heavy rocks and boulders are rolled and dragged along the seabed by strong currents and waves

Question 25

saltation

Answer 25

smaller pebbles and sediment are bounced along the seabed when waves momentarily lift them above the seabed

Question 26

solution (transportation)

Answer 26

dissolved minerals such as calcium carbonate from limestone is carried invisibly due to being subjected to acidic water

Question 27

what is the solution in water of limestone

Answer 27

calcium carbonate

Question 28

Longshore/Littoral Drift

Answer 28

transfer/flow mechanism responsible for moving sediment along the coastline and eventually out to sea Key component of the sediment cell

Question 29

how does LSD work

Answer 29

swash acts on an angle similar to prevailing wind Backwash occur directly perpendicular to the beach under gravity

Question 30

When does deposition occur

Answer 30

when the velocity of water falls below a critical value so that a particular size of particle can no longer be transported

Question 31

why is sediment deposition important

Answer 31

Creates depositional landforms which are sinks Considered both inputs and outputs in coastal systems

Question 32

what is a sediment sink

Answer 32

a store of sediment

Question 33

example of a high energy coastal environment in the UK

Answer 33

the S coast of England Sand and clay are easily transported to leave behind heavier coarser pebble beaches

Question 34

example of a low energy coastal environment

Answer 34

tiver estuaries where even the smallest clay particles drop to the seabed and form mudflats. Some sediment may be carried offshore as well to forom sandbanks