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ABC News: Mapping the sea floor

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ABC News: Mapping the sea floor

SUBJECTS:  Maths, Technologies

YEARS:  5–6


Hydrographers chart the seabed and coastline, giving ships a map to help them avoid running into underwater trouble.

Use this clip as a context for exploring the mapping of the sea floor. Think about scale and how to indicate different depths using contour lines.


Things to think about

  1. 1.Imagine that you have to map an underwater area known to contain three main geographical features located at a depth of 7 km, 2500 m and 200 m. What scale might you use if you had to draw all three features on a single piece of paper?
  2. 2.Notice the type of maps shown. They show a series of lines that curve around, representing different depths. The lines are called contour lines. Notice how the changes in depths are highlighted.
  3. 3.Create a sketch from above of an area 10 km by 10 km, showing features of a sea bed. Arrange geographical features including a trench with a depth of 7 km, a sandy sea floor at a depth of 2500 m and rocky outcrop 200 m deep. Develop a map of your sea floor, highlighting the depths using contour lines and a legend. Now draw a vertical cross-section of the 10 km by 10 km area. Show the position and depth of the three geographical features.
  4. 4.If you have a fish tank, place rocks and shapes on its floor to mimic an underwater seabed. Draw a map of your seabed from above. Work out a way to indicate changes in depth. Choose a side of the tank and draw a graph that shows the depth of water along the length of the side. For all measurements, use a scale of 1 cm = 1 m.



Date of broadcast: 10 Sep 2011


Copyright

Metadata © Australian Broadcasting Corporation and Education Services Australia Ltd 2012 (except where otherwise indicated). Digital content © Australian Broadcasting Corporation (except where otherwise indicated). Video © Australian Broadcasting Corporation (except where otherwise indicated). All images copyright their respective owners. Text © Australian Broadcasting Corporation and Education Services Australia is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0).

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