Science for you to try - Fast and furious: witnessing the birth of Africa's new ocean
The Earth's changing surface
The surface of the Earth made up of different plates which move at a very slow rate, but how far will they travel in 15 million years time? Try this activity and fast forward time to find out!
Procedure
You will need:
- To print this map before starting this activity
- Tracing paper
- The PowerPoint presentation which outlines the procedure for the activity
1. On your printed map mark the outlines of the coasts and other significant topographic features such as mountain ranges. Mark on the plate boundaries in a different colour.
2. Either cut along the plate boundaries, or perhaps better, use tracing paper to draw outlines and then cut out the tracings and slide back until they fit snugly next to each other. This is what the Afar region looked like 15 million years ago. Note: It is best to stick the Nubia tracing to the original map first, and slide Arabia and Somalia.
3. Once you have done this, mark matched points along the plate boundaries. See the PowerPoint presentation for more details.
4. Slide the plates back to their original positions so that you get a gap between the plates.
5. Now draw lines between the matched points on the different plates. See PowerPoint presentation for a diagram. This gives you a measure of the amount of opening that has occurred. If you print out the pdf map on A4, then 1 cm is 150 km. Alternatively, 10 degrees on the figure is approximately 1100 km.
6. To work out the future position of the plates (where they will be in 15 million years time), move the plates away from each other twice as far again. To do this, double the length of the lines and mark these on your map, however you should only to do this for two of the sets of lines – Nubia-Arabia and Nubia-Somalia.
7. Move the tracings of Arabia and Somalia to their new positions in 15 million years time. To check that it has worked, measure the distances between the match points separating Somalia and Arabia and check that they have doubled in length.
What's next?
Now that you’ve gone forward in time, what does the region of Afar look like?
1. Which plates have moved furthest apart?
Arabia – Nubia
Arabia – Somalia
Nubia – Somalia
2. Take the longest distance between your match points, how far have these plates moved in kilometres? (1 cm = 150 km)
3. This movement has taken 15 million years. How many kilometres do the plates move in one million years?
4. When you placed the plates directly next to each other (how they were 15 million years ago) the plates didn’t fit together perfectly. Why do you think this is?
Teacher's instructions
Go to main page of Teacher's Resource - Fast and furious: witnessing the birth of Africa's new ocean