Tuesday, October 25, 2011

Cavs Geography homework: 7.3

1 Name the three key geographical processes that shape the coastal environment.
They are Erosion, transportation and deposition.

2 What is wave refraction and why does it occur?
It is the wave energy being less focused in some areas and more focused in others due to headlands and the topography of the ocean floor.

Use a diagram to explain how wave refraction leads to the uneven distribution of wave energy along the coastline.

4 Name the most common erosional landforms found along the coastline.
The most common erosional features found along the coast are that of coastal headlands.

5 Describe the three wave action processes that shape headlands.
The are hydraulic action; waves crush against rock and the water compresses air in these gaps. Corrasion; waves carry rock an other materials across the rock shelf and wears away the rock in an abrasive fashion. Corrosion; waves break and wet the rocks which carry minerals in them, when the rock dries the salt crystallises and acts on the minerals in the rock to erode minerals.

6 Explain the operation of the erosion–accretion cycle.
Waves, wind and prevailing currents are all components of the erosion cycle. Wind creates swell and also carries of sediments, waves crush the coastal headlands and beaches and the prevailing currents carry deposits away form the shore creating sandbanks and such.

7 Name the three forces that shape depositional landforms on beaches.
They are the wind, waves and prevailing ocean currents.

8 Name the most common depositional landforms found along the coastline.
Beaches are the most obvious depositionl landforms found along coastlines.

9 Explain the process that forms coastal dunes. What role does vegetation play in their formation?
Coastal dunes are formed by wind, once the wind is deposited on the beach it is then subject to transportation, which is usually landward but is trapped by low lying vegetation. Thus forming sand dunes.

10 With the aid of a diagram describe the process of long shore drift. What role does this process play in transporting sand along the coast?


Long shore drift is when sand is deposited on beaches by waves that usually travel on an angle. The sand then travels in a zig-zag formation across the beach until it is finally deposited.

11 Select two erosional and two depositional landforms found on coasts. Sketch them into your notes and describe the processes that have formed each land form.







Two coastal land forms that come about as a result of erosion are that of a wave cut platform formed through the process known as Corrasion, and that of a blow hole formed by the process known as Hydraulic action.  Two coastal  ladfroms that form about as a result of decomposition are that of Sand dunes, formed through wind transportation of sand that is caught and accumulated by lowing lying vegetation. Also that of sandbars that occur during storms when large waves are created that erode the beach and the sand is taken some way out where it builds up as a sand bar which will eventually resettle on the beach.


12 What role does the foredune play in protecting coastal areas?
The fore-dune provides a buffer zone for the fragile dune vegetation located on the hind dunes.

13 Read the snapshot about the loss of one of the Twelve Apostles and use your knowledge of the coastal environment to answer the following:
a Where are the Twelve Apostles located?
they are located in Victoria at Port Campbell National Park
b Why are they a popular tourist destination?
Because they are one of Australia's most distinct coastal land forms
c Describe how the Twelve Apostles were formed.
They were formed as  result of the sea gradually eroding at the soft limestone
d What was London Bridge? What happened to this land form in 1990?
It was a natural arch that connected these off shore rocks to the mainland, it collapsed in 1990
e Do you think the collapse of the landforms along the coast could have been prevented? Explain your answer.
No it could not have been prevented, it must have been critically weakened after millions of years being subject to the ocean's corrosion powers. And the ocean will continue to erode. You can not hold back the ocean thus you can not prevent coastal erosion of these features.

Application
14 Imagine you are a park ranger employed at Port Campbell National Park. Prepare a brief talk that explains the formation and eventual destruction of the Twelve Apostles.
These landmarks were formed as a result of corrosion when the sea water after millions of years gradually corroded the soft limestone thus separating it from the land in isolated features as we see them today. Unfortunately they will not always stay in their beautiful and distinct shape as the ocean will continue to erode them until there is nothing left.

15 The local council has decided to buy back residential property located on a headland and a neighbouring fore dune that is subject to severe erosion. Local residents who own the property say the council is depriving them of their spectacular views, relaxed lifestyle and valuable property. Write a newspaper article that evaluates the council’s decision to buy back the properties. The article should present facts and consider a range of opinions about the issue. As a part of the article you will need to present an opinion on the property buy-back proposal.
The buying back of these properties is essential for the continual prosperity of these coastal environments. We humans are some of the most decisive factors in the changing environment. And as it happens the area in which these residents were located in is in fact subject to much erosion, it is probably also fair to say that it is a safer alternative for them, if the headland was to collapse with people living on it it could result in a great loss of life. Of course this is a hassle for the citizens and indeed most likely unnessessary but prevention is always better than the cure and it's better we act no and set the example for people to follow.

2 comments:

  1. Grate post.I really like this post!!I've read a few similar posts recently but I don't think I've ever read one that so perfectly expresses my own opinions on the matter.
    Buy House

    ReplyDelete
  2. Thank-you so much for the diagrams! I have been looking all over the net for those two diagrams with erosion/disposition on landforms and none of them had all the features that you have. Thanks so much - you saved me a lot of effort.

    ReplyDelete