4.3 (Distinctive Coastal Landscapes Are Influenced By Geology Interacting With Physical Processes)

Question 1

One time I tried to surf in Dover in the summer but the waves were low. But later on the in the year, when I came back, the waves were menacingly tall. Why then were they not like that before?

Answer 1

Because destructive waves are more common in winter.

Question 2

When sediment is removed from the coastline due to the waves, what do you call that process?

Answer 2

Coastal erosion.

Question 3

How are hard rock coasts different from soft rock coasts?

Answer 3

Hard rock coasts, unlike soft rock coasts, consist of resistant rocks (igneous granite) and resistant sedimentary (chalk).

Soft rock coasts consist of less resistant rocks like clays and shales.

Question 4

How are joints and faults the same?

Answer 4

They are both types of weaknesses that naturally weakens rock and influences coastal erosion.

Question 5

Joints are larger cracks than faults.

TRUE OR FALSE?

Answer 5

FALSE

Question 6

Where are you most likely to find a combination of erosional and depositional landforms?

Answer 6

Discordant coastlines.

Question 7

Where are you most likely to find erosional landforms?

Answer 7

Concordant landforms

Question 8

In concordant coastlines, rock strata are… to the coastline.

Answer 8

parallel

Question 9

Which type of coastline would you be most likely to find coves and cliffs; bays?

Answer 9

Concordant

Question 10

Which type of coastline would you be most likely to find bays and beaches; arch stack and stump, headland?

Answer 10

Discordant

Question 11

Fill in the missing words:

…is the action and force of water being forced into cracks in the rock. The …increases and …. Rock chips off the and the crack gets ….

Answer 11

Hydraulic action

Pressure

Bigger

Question 12

Fill in the missing words:

Abrasion is when rocks are … up by … and … or … against the …. This action …… the rock and it is … removed.

Answer 12

Picked

Waves

Thrown

Scraped

Cliffs

Wears

Gradually

Question 13

Fill in the missing words:

Solution is when the … becomes very slightly …. This is caused by … near to the …. This … rocks such as ….

Answer 13

Sea

Smoother

Vegetation

Cliffs

Dissolves

Limestone

Question 14

Fill in the missing words:

Attrition is the process where rocks ,that are held within the … … into …. Gradually the rocks become … and ….

Answer 14

Waves

Crash into

Each other

Smaller

Acidic

Question 15

Located off the coast of Pebble Beach in Northern California, the Ghost Trees’s waves are towering. And what are these waves dependent on for power? And what are the factors that affect this thing that affects the power of the waves ?

Answer 15

The wind

The factors that affect the wind’s power are:

How strong the wind is (strength).

How long the wind blows for (duration).

How far the wind travels (fetch).

Question 16

Where in the UK are the most powerful waves and why?

Answer 16

The most powerful waves in the UK are found on the west coast of the UK/Ireland in winter because the west coast has the longest fetch (6000km); its dominant wind direction is southwesterly and coincides with the fetch, making that the reason why they are the most powerful.

Question 17

Name all seven characteristics of destructive waves.

Answer 17

Short wave length
High wave height
Common in winter
Stronger backwash than swash
Removed sediment from the beach through erosion
Plunging waves downwards
High wave frequency (10-14 waves per minute)

Question 18

Name all seven characteristics of constructive waves.

Answer 18

Long wave length
Low wave height
Common in summer
Stronger swash than backwash
Adds sediment to the beach through deposition
Surging waves forward
Low wave frequency (6-8 waves per minute)

Question 19

Write the full process of a cave,arch,stack and stump.

Answer 19

Large crack,opened up by hydraulic action occurring a weakness in the headland (can come in the form of a fault as well as a crack).

The crack becomes larger

The cave breaks through the headland forming a natural ARCH.

The arch is eroded and collapses. Before that happens, the roof of the arch is weathered by chemical and biological processes. The base of the arch erodes creating a wave cut notch that is unsupported and collapses. The arch then becomes wider with more erosion and the roof is unsupported. The roof then finally collapses.

This leaves a tall rock STACK which is a single standing piece of rock.

The stack is eroded forming a STUMP. and this happens when the base of the stack erodes creating a wave cut notch. The stack is unstable and will collapse. The stump left at the end of the process, is only visible at low tide.

Question 20

One day I Mr Hyde was walking along a nice sheet of sediment and just realised the land I was walking of was spit. And to my right I spotted a salt marsh.

How did it come to this?

Answer 20

It all happened due to longshore drift and this is the full process:

Behind the headland, a sheltered area is present which receives lower energy waves- deposition occurs here.

The longshore drift moves sediment along the coastline

The heaviest, largest material is dropped first by the headland

A sudden change in coastline is required for a SPIT to occur

Gradually, smaller sediment is dropped and the spit grows

A secondary wind direction and secondary longshore drift direction occurs. This creates a “re-curved” end to the spit

The spit will not reach all the way across because of the deep water and river currents

Waves do not reach behind the spit and the water is calmer with less energy. Deposition creates SALT MARSHES eco-systems.

Question 21

Describe the full process of longshore drift.

Answer 21

Prevailing wind direction from the SW.

Waves approach beach at the same direction as prevailing wind

Swash moves sediment up beach in the same direction as the wind

Backwash moves sediment down the beach at a right angle due to gravity

The next waves pick up sediment

The sediment moves along the coastline.

Question 22

How do interlocking spurs form?

Answer 22

First vertical erosion is what happens, as the river’s discharge, meaning the amount of water in a river, is low in the upper course and so the river only has enough energy to erode downwards , and it erodes down because of erosion. The large amounts of gravitational potential energy in the upper course.

The land next to the river ie valley’s sides are then slowly broken through weathering.

The weathered material is then transported via gravity and rainfall towards the river channel. The transportation rate depend on the weather and gradient of cliff (rapid movements like soil creep that can happen in wet conditions). This process as a result steepens the valley sides.

Interlocking sours form where there are more resistant bands of rock (either more resistant types, or less faults/bedding planes) and the river cannot erode these.