Deposition And Waves 🌊 Weathering And Landslide

Question 1

Constructive waves 🌊

Answer 1

Weak backwash
Strong swash
Builds up beach

Question 2

Destructive waves

Answer 2

Short wave length but high frequency 10-14
Weak swash
Strong back wash
Remove sediments of the beach

Question 3

Why are constructive waves, constructive waves

Answer 3

They have low wave frequency but high wave length
These waves build up the beach because it uses all of its energy in the swash and moving materials up the beach
energy is from storms hundreds of miles away

Question 4

Why are destructive waves destructive waves

Answer 4

Sufficient power to erode beach

Weak swash as little material is left

Question 5

Features of a destructive wave beach

Answer 5

Caves arches stacks stumps will be created

removal of the sand and land

Question 6

Longshore drift

Answer 6

but if they approach at an angle measurements will be moved along the beach as a ‘zigzag ‘pattern is it called longshore drift

Question 7

What is longshore drift responsible for

Answer 7

longshore drift was responsible for a number of important coastal landforms including beach spits

Question 8

Movement on a Beach depends on what

Answer 8

The movement of sediment on a beach depends on the direction the waves approach the coast

where the waves approach ‘head on ‘ sediments is simply moved up and down the beach

Question 9

Transport on to the beach

Answer 9

Load is transport in the by waves

the larger the load the greater the velocity is needed to transport it

Question 10

How is the load carried

Answer 10

the lightest load is carried in suspension or saltation

a heavy load is moved out of the Beach by traction

Question 11

What

Is deposition

Answer 11

Deposition results in more sediments staying on the beach than is taken away by the backwash

Question 12

What causes deposition

Answer 12

Low energy sheltered bays constructive ways are the main reason
large sources of sediments updrift e.g. rapidly eroding Headland where engineered structures like groynes trap sediment on the updrift side

Question 13

Where does Coastal deposition take place

Answer 13

This takes place in areas where the flow of water slows down

Question 14

Where does coastal deposition take place

Answer 14

Waves lose energy in sheltered bays and where water is protected by spit or bars hear sediments can no longer be carried or moved and is therefore deposited

Question 15

What is weathering

Answer 15

Weathering is the breaking down of rocks it is caused by day-to-day changes in the atmosphere extremes of temperature and rainfall

Question 16

What is cliff collapse

Answer 16

It’s caused by weathering this weakens or decays rocks in the original place or close to the ground surface

Question 17

Types of cliff collapses

Answer 17

Mechanical chemical biological

Question 18

Mechanical cliff collapse

Answer 18

Disintegration of Rocks when this happens piles of rock fragments scree can be found at the foot of cliff

Question 19

Chemical weathering

Answer 19

Rainwater which is acidic this dissolve types of rocks e.g. limestone

Question 20

Biological weathering

Answer 20

E g plants and animals plant roots grow in cracks in the rocks animals such as rabbits Burrow into weak rock e.g. sand

Question 21

Freeze t h a w

Answer 21

Water enters holea night water freezes it expands then it thaws and create cracks

Question 22

Salt weathering

Answer 22

Sea water has salt water evaporates and leaves salt crystals crystals grow and expand

this causes pressure and cracks

Question 23

Chemical weathering .2

Answer 23

Remember the acidic water touches something alkaline e.g. limestone

Question 24

Mass movement

Answer 24

Downward movement or sliding of material under the influence of gravity

Question 25

Mud slide

Answer 25

Mud slide are usually wet rapid and tend to occur where slopes are steep over 10 degrees

Question 26

Where do mudslide take place

Answer 26

they usually happened where vegetation cover is little so it cannot hold the soil in place they happen after a period of heavy rain at the base of mudslide the soil spreads out to make a lobe

Question 27

Slumping

Answer 27

Slump has a concave slip plane so material is rotated backwards into the cliff face as it slips

Question 28

An example of slumping

Answer 28

Barton on Sea Hampshire the cliff is slumping at up to 30 cm per day

Question 29

Mudslide case study example

Answer 29

Monmouth beach lyme Regis Dorset

Question 30

Rock slide

Answer 30

A rockslide is where a large amount of rock slides down a cliff
this happened along fairly straight slip plane where rocks fall as a block which maintains contact with the cliff the leading edge of the slide collect as pile of rocks on the beach or in the sea

Question 31

Where does landslides happened in

Answer 31

The cliffs in the Jurassic Coast near Durdle Door in Dorset has suffered from large landslide in recent years

Question 32

Why do landslidesHappened

Answer 32

Slides it happened on steep Cliff all weaken by weathering
Heavy rain infiltrate the soil and circulate down into the rock
the now heavier mass Falls away along at the slip plane which is a line of weakness such as faults or bedding clean a slide happens quickly It Starts by tearing away vegetation on the top edge of the cliff
once the slide has begun the descent is aided by lubrication from the wet rocks below