Year 9, unit 2
Plate tectonics
Name: .......................................................................... Class: .......................... Date: ......................
Lesson 2: Develop a theory
Extension worksheet:
Earth’s changing continents
During the last 200 million years, the original giant world landmass, Pangaea, has
broken apart to form the seven continents we have today. These continents are
continuing to break apart.
Part A
1. Investigate the complex Rift Valley on the African continent using this website:
Wood, J and Guth, Alex, (n.d.) ‘East Africa's Great Rift Valley: A Complex Rift
System’, Geology.com http://geology.com/articles/east-africa-rift.shtml (2013)
a. Draw a map to show the relationship between the Afar Triangle, the Arabian
Plate, the African Plate (that is in the process of splitting into the Somali Plate)
and the Nubian Plate. Show the direction of plate movement.
b. Why is the Afar region of Ethiopia referred to as a triple junction?
c. Explain how the forces are widening the Rift Valley further south in the African
continent.
Part B
1. Apply ideas from Part A, and your knowledge of Australia’s position in relation to
the plates to predict whether or not Australia will to be torn apart due to
continental drift. Write a short paragraph supporting your prediction and include a
sketch-map of the relevant continental plates.
Part C
1. Predict the position of the present continents in 100 million years time. Present
this on a world map showing the new position of the current landmasses. On your
map show the direction of forces acting on these landmasses.
2. Check your predictions with those made on these sites:
‘Earth 100 million years from now’, YouTube (3:19 min)
http://www.youtube.com/watch?v=uGcDed4xVD4
‘Continents in Collision: Pangaea Ultima’ NASA Science News,
http://science.nasa.gov/science-news/science-at-nasa/2000/ast06oct_1/ (6
October 2000)
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