Learning Intention: Students will understand that the theory of plate tectonics explains global patterns of geological activity and continental movement. They will recognise the major plates on a world map, model sea-floor spreading and relate fold mountains, volcanic and earthquake activity to plate boundaries. They will relate the extreme age and stability of a large part of the Australian continent to it’s plate tectonic history.
Success Criteria: Students will produce a poster, slideshow, video or other digital product that explains the evidence that supports the theory of plate tectonics. Their work will include annotated world maps, diagrams of the structure of the earth and use scientific terminology (synclines, anticlines, tectonics, continental drift, convergent, divergent, subduction etc).
Today we watched a Clickview video “Global Tectonics: Competing Theories” that discussed the work of Copernicus, Galileo, Ortelius, Wegener and Hess and how their discoveries have changed human understanding of the way the earth works.
- Copernicus believed that the earth was at the centre, with the other stars and planets orbiting around it.
- Galileo’s theory, supported by many nights with a telescope, was that the sun was in the centre, with the earth orbiting around it. He also discovered mountains in the moon, the moons of Venus and that the milky way was made up of starts.
- The Dutch mapmaker, Abraham Ortelius, noticed that the shapes of Africa and South America fitted together like a jigsaw.
- Alfred Wegener, a German meteorologist, was the first to suggest that continents were once joined together. Evidence for this is in the form of similar plants, animals and fossils that exist on once-joined land masses (eg. South America, Australia and Antarctica once formed Gondwana.)
- Hess’s underwater exploration in the deep ocean led to the discovery of sea-floor spreading.
- Some scientists believe in the ‘global expansion theory’ that states the earth was once 60% of it’s present size.
Check out this You Tube video from National Geographic, “The Early Earth and Plate Tectonics”. If the continents are still moving, where will they be in 250 million years? The New York Times reported on some recent research that changes our understanding of heat conduction in the “Earth’s Core – the enigma 1,800 miles below“.