7.4 Questions

7.4 Questions

1.    Coastal management is developing ways to protect the coastal environment and preserving it's ecosystem

2.    Sea walls, breakwaters and groynes

3.     

Description	Advantages	Disadvantages
Sea walls are walls that are constructed normal to replace foredunes	Protect property	Scenic appeal reduced
Breakwaters are walls constructed from rivers into the ocean	Stabilize rivers	Rapidly changes erosion, transportation and deposition patterns
Groynes are constructed at right angles to the shore	Stop build up from longshore drift	Sand accumulates to one side
Beach nourishment is the moving of sand by cranes	Evens out the beach and looks more natural	It is expensive and is very ongoing
Coastal dune preservation involves managing dunes	Helps to preserve natural wonder of area	Requires extensive effort

4.    It is necessary to use a variety of techniques because because usually the problem requires several strategies as well as strategies to try and reduce the impact on the environment.

5.     

A.   Breakwaters

B.   Coastal dune preservation

C.   Beach nourishment

D.   Sea wall

UPDATED - Cortes Bank Big Wave Surfing Science

Cortes Bank is a shallow chain of underwater mountains about 188 kilometers west of Point Loma San Diego, USA. It used to be an island off the coast of California but when the ice age hit, it sunk below the waters surface. Nowadays it is also the home to big wave surfing. The mountains are very close to the surface of the ocean (about 1 m at the highest point, Bishop Rock) and therefore allow for easier refraction and allowing more energy to be compressed into a small area.

VIEW OF CORTES BANK FROM UNDER THE WATER:

The big waves only occur in American Winter (December through February). It only forms in winter because the water moisture in the air is much easy to condense to droplets in cold weather rather than hot weather where is evaporates.

This is very different to most surfing spots because it is in open ocean. The light wind, low tide and 'perfect' storm (big storm swells from the north-west from the cold arctic) also affect the size and occurring of the big waves. Big waves also occur when there are big storm swells, which occur often in the isolated ocean space.

The wave height of these waves can get up to 100 feet or 30 meters tall when the conditions are perfect. This happened in January of 2001. This may have occurred several times before but because only within the last 2 decades has the jet ski been invented, little has been known about these waves. With the help of the jet ski towing ability, the surfers were taxied to the huge waves.

7.3 Questions

1. The three key geographical processes that shape the coastal environment are erosion, transportation and deposition.
2. Wave refraction is the bending of waves due to headlands and the contours of the ocean floor.
3.  

    

     
      4. Headlands are the most common erosional feature found on coasts

      5. The three wave action processes are hydraulic action, corrasion and corrosion.
      6. During severe storms, beaches can lose large quantities of sand through erosion from  
           waves. The sand will form sand bars and when they are eroded away and deposited 
           back onto the beach, restoring the beach to its former state.
      7. The three forces that shape depositional landforms on the beach are wind, waves and 
           prevailing ocean currents.
      8. Beaches are The most common depositional landforms found along the coastline
      9. Coastal dunes are formed by the wind blowing sand into low lying vegetation which block 
           the sand from being transported any further. The low lying vegetation is important in the  
           formation because it 'clogs' the sand from being transported.
     10. 

    Long-shore Drift is important in moving sand along the coast through the sand being pushed by waves up the beach than the backwash brings the sand back into the ocean. As seen in the diagram above, the waves hit the sand at an angle than the backwash pulls the sand back at about a 90 degree angle.
    11. i) Tombolos - In shallow water, the eroded materials are kept in one place due to the refracting waves, thus causing land to stick up.

         ii) Sand Bar - When large storms occur, sand on the beaches are pulled out to see through the backwash which get deposited in large bars of sand

        iii) Natural Bridge - the corrasion and corrosion of cliffs bases begin to become eroded and ware away. The water normally only reaches a certain height thus not eroding the top and leaving a bridge.

      iv) Sea stacks - occur when soft limestone cliffs are gradually eroded away until it is separated from land and are stacks of limestone.

 12. Foredunes play an important role in the protecting of coastal areas because they provide a 'buffer zone' for dune vegetation. This helps the vegetation to grow back quickly if eroded. 

 13. 

      a) Great Road in Victoria

      b) popular tourist location, made 20 million years ago and very rare

      c) wave erosion

      d) A bridge that linked the mainland to offshore rocks which collapsed in 1990

      e) no, because erosion occurs naturally and is almost impossible to prevent

 14. The Apostles were a naturally occurring 'sea stack' which is a limescale stack that has been separated from the land due to erosion. This 'apostles' were formed over 20 million years ago and were about 45 meters tall. They weren't always 'sea stacks'. There was a natural bridge that connected them to the mainland which was called London Bridge, which collapsed in 1990. Many of the 12 'apostles' have collapsed and the latest being in 2005.

 15. WARNING! THE LOCAL COUNCIL IS COMING FOR YOUR PROPERTY! The local council has been buying back coastal land foredune is subjected severe erosion. Local residents are outraged by this because they believe that the local council is depriving them of the spectacular views, relaxed lifestyle and valuable property. This is an outrage that the whole community should stand up against. Why should you, the owner of a magnificent property, have to move just because the council is worried about the foredune. The council could quite easily replace the foredune which a synthetic foredune to create the needed buffer zone without the risk of erosion. I believe that action must be taken

     

Big Waves

Pre-viewing:

1. Where do ocean waves come from? What gets them started? Waves come from far out in sea from winds blowing on the top of water and generate energy to keep the wave going.
2. What do you think a surfer should know about waves before they try and ride a wave while surfing? They should know about what kind of swell it is and when the wave is going to break.

Question for the Video:

1. Observe all the waves that you see and describe how they form and break. Use as many words found in the segment for you descriptions. They are formed by the wind thousands of miles away and break once they hit a reef and 'jump'. The ocean floor is mainly flat and than hits the reef, slowing part of it down, and drawing in the wave energy to one spot.
2. Describe how waves are formed, how they originate, and how they are measured? Waves are formed with low pressure and high pressure systems generate energy when they come in close contact with each other. The wind generates energy into the ocean and pushes them towards the shorelines. They are measured by periods, height, and wave length.
3. What is a maverick wave and what is special about the way it is formed? A maverick wave is a 'big' wave found in northern California and is special because it only happens in winter and when the ocean floor is flat leading up to the reef.
4. How is energy stored and transferred during wave? Energy is stored by the continuous movement of energy over a long period of water and combining together and is transferred throught the water through the constant circling of water.
5. List any kind of advice given by the surfers about how to survive these “big waves.”
• Respect the waves
• Know when its going to break
• Waves 'jump' when hit the reef
• Once 'jumped' waves are about 2 times the size of the original wave before the reef
• Only do it if you are experienced

7.2 Questions - Waves

1. The wind forms ripples, than these form wavelets and finally waves.
2. A fetch is the distance wind travels one the ocean to form a wave. They are important factor because the waves speed and size is determined by the strength of the wind and length of the fetch.
3. The waves in the open ocean are mainly small and are only influenced by the wind which differs to waves closer to the shore which have the sand to influence the strength and frequency in which they occur
4.  

     5. 

   

   6. Spilling waves : Break far from shore and is mainly white foam when reaches shore, good for bodysurfing

       Plunging waves: Break near shore, form tubes, good for board riders

       Surging waves: Break on the shore, cause erosion, roll up steep face

   7. Wind swell is marked by a short wavelength and high frequency as opposed to a ground swell which is the opposite, a long wavelength and less frequent waves.

7.1 Questions - Geographical Issues

1. The coast is a unique ecosystem in that it is extreme volatile and always changing. By having a coastal settlement the ecosystem must not 'evolve' to make sure that the inhabitants can live consistently without radical change.
2. The aim of coastal management strategies is to make sure that when human have been placed within an ecosystem, the ecosystem will not be negatively affected to a deadly level.
3. The trend that has been labeled 'sea-change' is the moving from the city to a coastal town that is smaller and more relaxed
4. One government response to 'sea-change' is residential cap which restricts how many people can live within a hectare.
5. Four geographical issues are and how humans are involved are: inappropriate develop (people building more than needed and big buildings where not needed), population doubling due to holidays (puts pressure of coast through waste), beaches getting more people during holidays (more rubbish and pressure doubles on certain areas of land), pollution after a storm (rubbish is flowed into drain and straight to beaches and oceans).
6. They need to have a good understanding of the past to ensure that they can accurately predict the future.  This is to make sure that no ecosystem is dramatically changed and to make educated decisions on coastal management.
7. Dear local council, I am writing to you to voice my opinion on the resent apartments that have been built on beachfront property in a small urban town. This new building my bring in tourism, money and the chance for more people to live in such a great town, but they are disrupting the coastal views and lifestyle of those who live there. It affects the quite, calm beach life that many people strive for, as well as the waterfront views of the under crowded beaches. I bring this up to question the building of high density buildings in a low density area, and that this must not continue.

Geography Extended Response

Communities never stay static and within the worlds globalisation and population ever-expanding, communities must change and adapt to the growing demand within the area. An example of this is St Ives in Sydney. Majority of St Ives are either of Jewish descent or of South African descent. With a population of 14207 within the 14.39 km2 and within an urban area of Sydney, St Ives is ever growing. This suburb, within the North Shore, is a sought after part of Sydney both for its schools and its location in comparison to the city. With more and more people wanting to move within the area, St Ives is having to develop less low density housing and more medium density housing (less houses and more apartment blocks). The effect of the change within the area means that St Ives is becoming more like a confined metropolis rather than a quite suburb.