coastal processes

Question 1

formation of a wave

Answer 1

wind moves across the water surface creating small ripples via frictional drag. Towards the coastline, the seabed gets shallower and the water particles become more elliptical causing wave height to increase. Water backs up behind the wave until it breaks and surges onto the beach

Question 2

factors affecting the size and energy of a wave

Answer 2

duration of wind
strength of wind
size of fetch

Question 3

what are the two wave types

Answer 3

constructive and destructive

Question 4

features of a constructive wave:

Answer 4

long wave length
strong swash
weak backwash
forming a gentle sloped beach

Question 5

features of a destructive wave:

Answer 5

short wave length
weak swash
strong backwash
forming a steep sloped beach

Question 6

what is wave refraction?

Answer 6

where waves turn and loose energy around a headland or uneven coastline. Energy is then concentrated on the headland creating erosional landforms. energy dissipates in bays leading to depositional landforms

Question 7

6 types of marine erosion:

Answer 7

hydraulic action
cavitation
corrasion
abrasion
solution
attrition

Question 8

define hydraulic action

Answer 8

water pressure breaks down sediment

Question 9

define cavitation

Answer 9

compression of air in joints as waves crash against cliffs causing sea water to be compressed, forcing rock apart

Question 10

define corrasion

Answer 10

a type of chemical erosion breaking down the rocks

Question 11

define abrasion

Answer 11

rocks erode by being thrown against cliffs etc

Question 12

define solution

Answer 12

when sea water dissolves certain types of rocks

Question 13

define attrition

Answer 13

when material carried by waves hit and knock against each other

Question 14

what are sub-aerial processes

Answer 14

weathering and mass movement

Question 15

define mass movement

Answer 15

material moving downslope via force of gravity

Question 16

define weathering

Answer 16

the break down of rocks in situ

Question 17

methods of marine transportation

Answer 17

traction
saltation
suspension
solution
longshore drift

Question 18

define traction

Answer 18

roll along the sea bed

Question 19

define saltation

Answer 19

bounce along the sea bed

Question 20

define suspension

Answer 20

carried in the flow of water

Question 21

what is longshore drift

Answer 21

when waves hit a beach at an angle due to prevailing wind direction, pushing sediment this way up the beach

Question 22

what are sediment cells

Answer 22

coastlines split into sections usually by prominent headlands. Within these is dynamic equilibrium is achieved as the movement of sediment is contained